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1.
Arq Gastroenterol ; 52(2): 156-60, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26039837

RESUMO

BACKGROUND: Several studies have reported that severe reflux esophagitis is rare in infants despite the well known high occurrence of regurgitation in early infancy. There is evidence of the importance of saliva for the pre-epithelial protection of the esophageal mucosa. RESULTS: A longitudinal study conducted on healthy infants indicated that the stimulated capacity of saliva secretion (saliva output per kg of body weight) was significantly higher during their first year of age compared to older children and adults. In addition, this secretion pattern was also observed in low weight newborns during the first weeks of life and persisted in infants with severe protein-calorie malnutrition (marasmus). CONCLUSION: The greater ability to secrete saliva is an important physiological condition that may protect the infant from acid/pepsin aggression to the esophagus during early stages of development.


Assuntos
Esofagite Péptica/fisiopatologia , Saliva/metabolismo , Esofagite Péptica/prevenção & controle , Feminino , Humanos , Masculino , Saliva/fisiologia
2.
Arq. gastroenterol ; 52(2): 156-160, Apr-Jun/2015. graf
Artigo em Inglês | LILACS | ID: lil-748165

RESUMO

Background Several studies have reported that severe reflux esophagitis is rare in infants despite the well known high occurrence of regurgitation in early infancy. There is evidence of the importance of saliva for the pre-epithelial protection of the esophageal mucosa. Results A longitudinal study conducted on healthy infants indicated that the stimulated capacity of saliva secretion (saliva output per kg of body weight) was significantly higher during their first year of age compared to older children and adults. In addition, this secretion pattern was also observed in low weight newborns during the first weeks of life and persisted in infants with severe protein-calorie malnutrition (marasmus). Conclusion The greater ability to secrete saliva is an important physiological condition that may protect the infant from acid/pepsin aggression to the esophagus during early stages of development. .


Contexto Vários estudos têm indicado que a esofagite de refluxo é rara em lactentes no primeiro ano de vida a despeito da elevada ocorrência de regurgitação nesta fase da vida. Há evidências da importância da saliva para a proteção pré-epitelial da mucosa esofágica. Resultados Um estudo longitudinal conduzido em lactentes saudáveis indicou que a capacidade estimulada da secreção de saliva (volume de saliva/kg de peso) foi significativamente elevada no primeiro ano de vida comparada com crianças com mais idade e adultos jovens. Este padrão também foi observado nas primeiras semanas de vida de recém-nascidos com baixo peso e persistiu em lactentes com desnutrição proteico-calórica grave (marasmo) Conclusão A grande habilidade para secretar saliva é uma importante condição fisiológica que pode proteger o lactente da agressão ácido/péptica do esôfago durante os primeiros estágios do seu desenvolvimento. .


Assuntos
Feminino , Humanos , Masculino , Esofagite Péptica/fisiopatologia , Saliva , Esofagite Péptica/prevenção & controle , Saliva/fisiologia
3.
Arq. bras. cardiol ; 104(2): 144-151, 02/2015. graf
Artigo em Inglês | LILACS | ID: lil-741140

RESUMO

Background: In pathological situations, such as acute myocardial infarction, disorders of motility of the proximal gut can trigger symptoms like nausea and vomiting. Acute myocardial infarction delays gastric emptying (GE) of liquid in rats. Objective: Investigate the involvement of the vagus nerve, α 1-adrenoceptors, central nervous system GABAB receptors and also participation of paraventricular nucleus (PVN) of the hypothalamus in GE and gastric compliance (GC) in infarcted rats. Methods: Wistar rats, N = 8-15 in each group, were divided as INF group and sham (SH) group and subdivided. The infarction was performed through ligation of the left anterior descending coronary artery. GC was estimated with pressure-volume curves. Vagotomy was performed by sectioning the dorsal and ventral branches. To verify the action of GABAB receptors, baclofen was injected via icv (intracerebroventricular). Intravenous prazosin was used to produce chemical sympathectomy. The lesion in the PVN of the hypothalamus was performed using a 1mA/10s electrical current and GE was determined by measuring the percentage of gastric retention (% GR) of a saline meal. Results: No significant differences were observed regarding GC between groups; vagotomy significantly reduced % GR in INF group; icv treatment with baclofen significantly reduced %GR. GABAB receptors were not conclusively involved in delaying GE; intravenous treatment with prazosin significantly reduced GR% in INF group. PVN lesion abolished the effect of myocardial infarction on GE. Conclusion: Gastric emptying of liquids induced through acute myocardial infarction in rats showed the involvement of the vagus nerve, alpha1- adrenergic receptors and PVN. .


Fundamento: Distúrbios da motilidade do intestino proximal no infarto agudo do miocárdio podem desencadear sintomas digestivos como náuseas e vômitos. O infarto do miocárdio ocasiona retardo do esvaziamento gástrico (EG) de líquido em ratos. Objetivo: Investigar se existe a influência do nervo vago (VGX), adrenoreceptores α-1, receptores GABAB do sistema nervoso central e participação do núcleo paraventricular (NPV) do hipotálamo no esvaziamento gástrico (EG) e complacência gástrica (CG) em ratos infartados. Métodos: Ratos Wistar (n = 8-15) foram divididos em: grupo infarto (INF), sham (SH) e subdivididos. O infarto foi realizado por ligadura da artéria coronária descendente anterior. A complacência gástrica foi estimada com curvas pressão-volume. Realizada vagotomia por secção dos ramos dorsal e ventral. Para verificar a ação dos receptores GABAB foi injetado baclofeno por via intra ventrículo-cerebral. Simpatectomia química foi realizada com prazosina intravenosa (iv), e na lesão do núcleo paraventricular do hipotálamo foi utilizada corrente elétrica de 1mA/10s, com esvaziamento gástrico determinado por medição da retenção gástrica (% RG) de uma refeição salina. Resultados: Não houve diferença significativa na CG. A vagotomia (VGX) reduziu significativamente a %RG; no grupo INF, o tratamento intra ventrículo-cerebral (ivc) com baclofeno reduziu significativamente a % RG; não houve conclusivamente envolvimento dos receptores GABAB em retardar o EG; o tratamento intravenoso com prazosina reduziu significativamente a %RG no grupo INF. A lesão do NPV aboliu o efeito do infarto do miocárdio no EG. Conclusão: O nervo vago, receptores α-adrenérgicos e núcleo paraventricular estão envolvidos no retardo do esvaziamento gástrico no infarto agudo do miocárdio em ratos. .


Assuntos
Animais , Masculino , Esvaziamento Gástrico/fisiologia , Infarto do Miocárdio/fisiopatologia , Núcleo Hipotalâmico Paraventricular/fisiopatologia , Receptores Adrenérgicos alfa 1/fisiologia , Receptores de GABA-B/fisiologia , Nervo Vago/fisiopatologia , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Baclofeno/farmacologia , Agonistas dos Receptores de GABA-B/farmacologia , Gastroparesia/fisiopatologia , Infarto do Miocárdio/complicações , Prazosina/farmacologia , Ratos Wistar , Fatores de Tempo , Vagotomia
4.
Arq Bras Cardiol ; 104(2): 144-51, 2015 Feb.
Artigo em Inglês, Português | MEDLINE | ID: mdl-25494017

RESUMO

BACKGROUND: In pathological situations, such as acute myocardial infarction, disorders of motility of the proximal gut can trigger symptoms like nausea and vomiting. Acute myocardial infarction delays gastric emptying (GE) of liquid in rats. OBJECTIVE: Investigate the involvement of the vagus nerve, α 1-adrenoceptors, central nervous system GABAB receptors and also participation of paraventricular nucleus (PVN) of the hypothalamus in GE and gastric compliance (GC) in infarcted rats. METHODS: Wistar rats, N = 8-15 in each group, were divided as INF group and sham (SH) group and subdivided. The infarction was performed through ligation of the left anterior descending coronary artery. GC was estimated with pressure-volume curves. Vagotomy was performed by sectioning the dorsal and ventral branches. To verify the action of GABAB receptors, baclofen was injected via icv (intracerebroventricular). Intravenous prazosin was used to produce chemical sympathectomy. The lesion in the PVN of the hypothalamus was performed using a 1 mA/10 s electrical current and GE was determined by measuring the percentage of gastric retention (% GR) of a saline meal. RESULTS: No significant differences were observed regarding GC between groups; vagotomy significantly reduced % GR in INF group; icv treatment with baclofen significantly reduced %GR. GABAB receptors were not conclusively involved in delaying GE; intravenous treatment with prazosin significantly reduced GR% in INF group. PVN lesion abolished the effect of myocardial infarction on GE. CONCLUSION: Gastric emptying of liquids induced through acute myocardial infarction in rats showed the involvement of the vagus nerve, alpha1- adrenergic receptors and PVN.


Assuntos
Esvaziamento Gástrico/fisiologia , Infarto do Miocárdio/fisiopatologia , Núcleo Hipotalâmico Paraventricular/fisiopatologia , Receptores Adrenérgicos alfa 1/fisiologia , Receptores de GABA-B/fisiologia , Nervo Vago/fisiopatologia , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Animais , Baclofeno/farmacologia , Agonistas dos Receptores de GABA-B/farmacologia , Gastroparesia/fisiopatologia , Masculino , Infarto do Miocárdio/complicações , Prazosina/farmacologia , Ratos Wistar , Fatores de Tempo , Vagotomia
5.
Arq Gastroenterol ; 47(3): 290-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21140092

RESUMO

CONTEXT: Gamma-aminobutyric acid (GABA) is a potent inhibitory neurotransmitter. There is evidence that GABA(B) receptors located in the dorsal complex and in afferent fibers of the vagus nerve participate in the control of gastrointestinal motility. OBJECTIVE: To assess the intracerebroventricularly (ICV) and intravenously (IV) effect of baclofen, a GABA(B) receptor agonist, on liquid and solid gastric emptying in rats. METHODS: Adult male Wistar rats weighing 250-300 g (n = 6-8 animals) were used. Gastric emptying of liquid test meals labeled with phenol red was evaluated by the determination of percent gastric retention (%GR) 10 and 15 min after orogastric administration of saline and 10% glucose meals, respectively. Baclofen was injected ICV (1 and 2 µg/animal) through a tube implanted into the lateral ventricle of the brain and was injected IV (1 and 2 mg/kg) into a tail vein. The gastric emptying of liquid was determined 10 or 30 min after ICV and IV baclofen administration, respectively. The gastric emptying of the solid meal was assessed by the determination of percent gastric retention 2 h after the beginning of the ingestion of the habitual ratio by the animal, consumed over a period of 30 min. Baclofen was administered ICV (1 and 2 µg/animal) or IV (1 and 2 mg/kg) immediately after the end of the ingestion of the solid meal. The control groups received vehicle (sterile saline solution) ICV or IV. RESULTS: The group of animals receiving baclofen ICV (2 mg/animal) presented a significantly lower (P<0.05, Tukey test) %GR (mean ± SEM) of the saline (18.1 ± 2.5%) compared to control (33.2 ± 2.2%). In the group receiving the drug IV, the gastric retention of the same test meal did not differ from control. ICV and IV administration of baclofen had no effect on the gastric emptying of the 10% glucose solution compared to control. ICV administration of 1 or 2 mg baclofen/animal significantly increased the gastric retention of the solid test meal (57.9 ± 6.5% and 66.6 ± 6.3%, respectively) compared to control (35.1 ± 4.4%). The same phenomenon was observed only with the IV dose of 2 mg/kg (71.9 ± 2.6%) compared to control (52.7 ± 2.8%). CONCLUSION: Baclofen administered: 1. ICV (2 µg/animal), but not IV, increased gastric emptying of a non-caloric isotonic liquid test meal (saline); 2. when administered ICV or IV, it had no effect of gastric emptying of a 10% glucose solution; 3) when administered ICV (1 and 2 mg/animal) and IV (2 mg/kg) it delayed the gastric emptying of the solid meal.


Assuntos
Baclofeno/farmacologia , Agonistas GABAérgicos/farmacologia , Esvaziamento Gástrico/efeitos dos fármacos , Animais , Glucose , Masculino , Fibras Nervosas/efeitos dos fármacos , Ratos , Ratos Wistar , Receptores de GABA-B/fisiologia , Cloreto de Sódio , Soluções
6.
Arq. gastroenterol ; 47(3): 290-296, jul.-set. 2010. ilus
Artigo em Inglês | LILACS | ID: lil-567312

RESUMO

CONTEXT: Gamma-aminobutyric acid (GABA) is a potent inhibitory neurotransmitter. There is evidence that GABA B receptors located in the dorsal complex and in afferent fibers of the vagus nerve participate in the control of gastrointestinal motility. OBJECTIVE: To assess the intracerebroventricularly (ICV) and intravenously (IV) effect of baclofen, a GABA B receptor agonist, on liquid and solid gastric emptying in rats. METHODS: Adult male Wistar rats weighing 250-300 g (n = 6-8 animals) were used. Gastric emptying of liquid test meals labeled with phenol red was evaluated by the determination of percent gastric retention ( percentGR) 10 and 15 min after orogastric administration of saline and 10 percent glucose meals, respectively. Baclofen was injected ICV (1 and 2 µg/animal) through a tube implanted into the lateral ventricle of the brain and was injected IV (1 and 2 mg/kg) into a tail vein. The gastric emptying of liquid was determined 10 or 30 min after ICV and IV baclofen administration, respectively. The gastric emptying of the solid meal was assessed by the determination of percent gastric retention 2 h after the beginning of the ingestion of the habitual ratio by the animal, consumed over a period of 30 min. Baclofen was administered ICV (1 and 2 µg/animal) or IV (1 and 2 mg/kg) immediately after the end of the ingestion of the solid meal. The control groups received vehicle (sterile saline solution) ICV or IV. RESULTS: The group of animals receiving baclofen ICV (2 mg/animal) presented a significantly lower (P<0.05, Tukey test) percentGR (mean ± SEM) of the saline (18.1 ± 2.5 percent) compared to control (33.2 ± 2.2 percent). In the group receiving the drug IV, the gastric retention of the same test meal did not differ from control. ICV and IV administration of baclofen had no effect on the gastric emptying of the 10 percent glucose solution compared to control. ICV administration of 1 or 2 mg baclofen/animal significantly increased the gastric retention of the solid test meal (57.9 ± 6.5 percent and 66.6 ± 6.3 percent, respectively) compared to control (35.1 ± 4.4 percent). The same phenomenon was observed only with the IV dose of 2 mg/kg (71.9 ± 2.6 percent) compared to control (52.7 ± 2.8 percent). CONCLUSION: Baclofen administered: 1. ICV (2 µg/animal), but not IV, increased gastric emptying of a non-caloric isotonic liquid test meal (saline); 2. when administered ICV or IV, it had no effect of gastric emptying of a 10 percent glucose solution; 3) when administered ICV (1 and 2 mg/animal) and IV (2 mg/kg) it delayed the gastric emptying of the solid meal.


CONTEXTO: O ácido gama-aminobutírico (GABA) é um potente neurotransmissor inibitório. Há evidências que receptores GABA>B localizados no complexo dorsal do vago e em fibras aferentes do nervo vago participam no controle da motricidade gastrointestinal. OBJETIVO: Avaliar o efeito intracerebroventricular (ICV) e intravenoso (IV) do baclofen, um agonista para receptores GABA B, sobre o esvaziamento gástrico de líquidos e de sólidos em ratos. MÉTODOS: Foram utilizados ratos adultos Wistar, machos, de 250-300 g (n = 6-8 animais). O esvaziamento gástrico das refeições de prova líquidas, marcadas com fenol vermelho, foi avaliado através da determinação da por cento de retenção gástrica, 10 e 15 min após administração orogástrica das refeições salina e de glicose a 10 por cento, respectivamente. As injeções ICV de baclofen (1 e 2 µg/animal) foram feitas através de uma sonda implantada no ventrículo lateral do cérebro e as injeções IV de baclofen (1 e 2 mg/kg) numa veia da cauda. O esvaziamento gástrico das refeições de prova líquidas foi determinado 10 ou 30 min após a administração de baclofen ICV ou IV, respectivamente. O esvaziamento gástrico da refeição sólida foi avaliado através da determinação da por cento de retenção gástrica 2 h após o início da ingestão da ração habitual do animal, ingerida durante 30 min. As administrações de baclofen ICV (1 e 2 µg/animal) e IV (1 e 2 mg/kg) foram feitas imediatamente após o término da ingestão da refeição sólida. Os grupos controles receberam ICV ou IV veículo (solução salina estéril). RESULTADOS: O grupo de animais que recebeu baclofen 2 mg/animal ICV apresentou retenção gástrica (média ± SEM) de salina (18.1 ± 2.5 por cento) significantemente menor (P<0.05, teste de Tukey) em relação ao grupo controle (33.2 ± 2.2 por cento). No grupo com administração IV da droga, a retenção gástrica da mesma refeição de prova não diferiu do seu controle. As administrações ICV e IV de baclofen não tiveram qualquer efeito no esvaziamento gástrico da solução de glicose a 10 por cento, em relação aos seus controles. A administração ICV de 1 ou 2 µg/animal de baclofen aumentou significativamente as retenções gástricas da refeição de prova sólida (57.9 ± 6.5 por cento e 66.6 ± 6.3 por cento, respectivamente) em relação ao grupo controle (35.1 ± 4.4 por cento). O mesmo fenômeno somente foi observado com a dose IV de 2 mg/kg (71.9 ± 2.6 por cento) em relação ao grupo controle (52.7 ± 2.8 por cento). CONCLUSÃO: O baclofen administrado: 1. ICV (2 µg/animal), mas não IV, aumentou o esvaziamento gástrico de uma refeição de prova líquida isotônica não-calórica (salina); 2. ICV ou IV, não teve efeito sobre o esvaziamento da solução de glicose a 10 por cento; 3) ICV (1 e 2 µg/animal) e IV (2 mg/kg) retardou o esvaziamento gástrico da refeição sólida.


Assuntos
Animais , Masculino , Ratos , Baclofeno/farmacologia , Agonistas GABAérgicos/farmacologia , Esvaziamento Gástrico/efeitos dos fármacos , Glucose , Fibras Nervosas/efeitos dos fármacos , Ratos Wistar , Receptores de GABA-B/fisiologia , Cloreto de Sódio , Soluções
7.
Acta cir. bras ; 23(6): 486-490, Nov.-Dec. 2008. graf, tab
Artigo em Inglês | LILACS | ID: lil-496749

RESUMO

PURPOSE: To evaluate the effect of hypoxic-ischemic brain injury over the gastric emptying of liquids in rats. METHODS: Fifty-two Wistar rats aged six weeks and weighing between 100g and 150g were divided in three groups. A Control group (C), a Sham group (S) undergoing sham procedure, and a Hypoxic-ischemic group (HI) consisting of 18 animals undergoing surgical ligature of the left carotid artery and exposure to hypoxic environment for three hours. Half of the animals were studied in the third day post-HI procedure (Early) and nine in the 14th day post-HI procedure (Late). Gastric emptying was evaluated by an infusion technique using fenolsulftalein as a marker. RESULTS: After the HI procedure, all animals displayed left eyelid ptosis, and six animals showed minor sideway gait. Histological examination confirmed de brain injury in all animals from the HI group. There was no statistical significant difference among the mean gastric retention values of the three groups neither in the Early nor in the Late evaluation. CONCLUSION: Isolated HI brain injury was not associated with delayed gastric emptying.


OBJETIVO: Avaliar o efeito de lesão cerebral hipoxico-isquêmica sobre esvaziamento gástrico (EG) de líquidos em ratos. MÉTODOS: Cinqüenta e dois ratos Wistar com seis semanas de idade e pesando entre 100g e 150g foram divididos em três grupos. Um grupo Controle (C), um grupo Sham (S) de 18 animais submetidos a manipulação da artéria carótida esquerda sem ligadura e um grupo Hipoxico-isquêmico (HI) que consistiu de 18 animais submetidos a ligadura cirúrgica da artéria carótida esquerda e exposição a ambiente hipóxico por três horas. Metade dos animais foi estudada no terceiro dia pós-procedimento (Precoce) e a outra metade no 14º dia pós-procedimento (Tardio). O EG de uma solução salina foi avaliado por uma técnica de infusão usando a fenolsulftaleína como um marcador. RESULTADOS: Após o procedimento de HI, todos os animais apresentaram ptose palpebral à esquerda e seis animais mostraram leve desvio da marcha. O exame histológico do cérebro confirmou lesão cerebral em todos os animais do grupo HI. Não foi observada diferença estatística significativa entre os valores médios da retenção gástrica dos três grupos nem nas observações Precoces nem nas Tardias. CONCLUSÃO: A lesão cerebral difusa isolada provocada por um episódio HI não esta associada com retarde de esvaziamento gástrico de uma refeição líquida não calórica.


Assuntos
Animais , Masculino , Ratos , Lesões Encefálicas/fisiopatologia , Esvaziamento Gástrico/fisiologia , Refluxo Gastroesofágico/fisiopatologia , Hipóxia-Isquemia Encefálica/fisiopatologia , Análise de Variância , Lesões Encefálicas/complicações , Lesões Encefálicas/patologia , Modelos Animais de Doenças , Refluxo Gastroesofágico/etiologia , Refluxo Gastroesofágico/cirurgia , Hipóxia-Isquemia Encefálica/complicações , Distribuição Aleatória , Ratos Wistar
8.
Acta Cir Bras ; 23(6): 486-90, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19030745

RESUMO

PURPOSE: To evaluate the effect of hypoxic-ischemic brain injury over the gastric emptying of liquids in rats. METHODS: Fifty-two Wistar rats aged six weeks and weighing between 100 g and 150 g were divided in three groups. A Control group (C), a Sham group (S) undergoing sham procedure, and a Hypoxic-ischemic group (HI) consisting of 18 animals undergoing surgical ligature of the left carotid artery and exposure to hypoxic environment for three hours. Half of the animals were studied in the third day post-HI procedure (Early) and nine in the 14th day post-HI procedure (Late). Gastric emptying was evaluated by an infusion technique using fenolsulftalein as a marker. RESULTS: After the HI procedure, all animals displayed left eyelid ptosis, and six animals showed minor sideway gait. Histological examination confirmed de brain injury in all animals from the HI group. There was no statistical significant difference among the mean gastric retention values of the three groups neither in the Early nor in the Late evaluation. CONCLUSION: Isolated HI brain injury was not associated with delayed gastric emptying.


Assuntos
Lesões Encefálicas/fisiopatologia , Esvaziamento Gástrico/fisiologia , Refluxo Gastroesofágico/fisiopatologia , Hipóxia-Isquemia Encefálica/fisiopatologia , Análise de Variância , Animais , Lesões Encefálicas/complicações , Lesões Encefálicas/patologia , Modelos Animais de Doenças , Refluxo Gastroesofágico/etiologia , Refluxo Gastroesofágico/cirurgia , Hipóxia-Isquemia Encefálica/complicações , Masculino , Distribuição Aleatória , Ratos , Ratos Wistar
9.
Arq Gastroenterol ; 43(3): 229-32, 2006.
Artigo em Português | MEDLINE | ID: mdl-17160240

RESUMO

BACKGROUND: There is evidence that nitric oxide plays a role in the decrease in gastric emptying induced by bacterial lipopolysaccharide. AIM: To evaluate the effect of pretreatment with Nw-nitro-L-arginine methyl to ester, one competitive inhibitor of the nitric oxide synthases, on the gastric emptying delay induced by lipopolysaccharide. MATERIAL AND METHODS: Male Wistar rats, SPF, were used after 24 h fast and 1 h-water withdrawn. The pretreatment was done intravenously with vehicle (saline) or N(w)-nitro-L-arginine methyl to ester in the doses of 0.5, 1, 2.5 e 5 mg/kg. After 10 min, the animals were treated iv with lipopolysaccharide (50 microg/kg) or received vehicle (saline). The gastric emptying was evaluated 1 h after the lipopolysaccharide administration. A saline solution containing phenol red was used as the test meal. The gastric emptying was indirectly assessed by the determination of percent gastric retention of the test meal 10 min after orogastric administration. RESULTS: The animals pretreated with vehicle and treatment with lipopolysaccharide have significant rise of the gastric retention (average = 57%) in comparison with the controls receiving only vehicle (38.1%). The pretreatment with the different doses of N(w)-nitro-L-arginine methyl to ester did not modify per se the gastric retention in comparison with the animals pretreated with vehicle. Pretreatment with N(w)-nitro-L-arginine methyl to ester with the dose of 1 mg/kg determined a discrete but significant reduction in the gastric retention (52%) of animals treated with lipopolysaccharide in comparison with vehicle-pretreated rats. Paradoxically, animals pretreated with 2.5 or 5 mg of N(w)-nitro-L-arginine methyl to ester/kg followed by treatment with lipopolysaccharide displayed a significantly higher gastric retention (74.7% and 80.5%, respectively) as compared to their controls, pretreated with the same doses of the inhibitor and treated with vehicle (40.5% and 38.7%, respectively) and to those pretreated with vehicle and treated with the same toxin. CONCLUSION: The pretreatment with N(w)-nitro-L-arginine methyl to ester at low dose (1 mg/kg) resulted in a discrete inhibition of the gastric emptying delay induced by lipopolysaccharide. Nevertheless, N(w)-nitro-L-arginine methyl to ester at higher doses (2.5 and 5 mg/kg) induced an enhancement of the lipopolysaccharide effect on gastric emptying, despite not interfering with the gastric emptying per se.


Assuntos
Inibidores Enzimáticos/farmacologia , Esvaziamento Gástrico/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Análise de Variância , Animais , Modelos Animais de Doenças , Masculino , Ratos , Ratos Wistar
10.
Arq. gastroenterol ; 43(3): 229-232, jul.-set. 2006. ilus
Artigo em Português, Inglês | LILACS | ID: lil-439787

RESUMO

RACIONAL: Há evidências de que o óxido nítrico participa do mecanismo de retardo do esvaziamento gástrico determinado pelo lipopolissacarídio bacteriano. OBJETIVO: Avaliar o efeito do pré-tratamento com Nw-nitro-L-arginine methyl ester, um inibidor competitivo das óxido nítrico-sintetases, sobre o fenômeno. MATERIAL E MÉTODOS: Utilizaram-se ratos, Wistar, machos, SPF ("specific-pathogen free"), adultos, adaptados às condições do laboratório, que após 24 horas de jejum alimentar foram pré-tratados endovenosamente com veículo (salina) ou Nw-nitro-L-arginine methyl ester nas doses de 0,5, 1, 2,5 e 5 mg/kg. No tratamento, administrou-se endovenosamente veículo (salina) ou lipopolissacarídio (50 µg/kg). O intervalo entre o pré-tratamento e o tratamento foi de 10 minutos, e entre este e a avaliação do esvaziamento gástrico foi de 60 minutos. O esvaziamento gástrico foi avaliado indiretamente através da determinação da retenção gástrica da solução salina marcada com fenol vermelho 10 minutos após administração por via orogástrica. RESULTADOS: Entre os animais pré-tratados com veículo, o tratamento com lipopolissacarídio determinou elevação significativa da retenção gástrica (média = 57 por cento) em relação aos tratados com veículo (38,1 por cento). O pré-tratamento com as diferentes doses de Nw-nitro-L-arginine methyl ester não modificou a retenção gástrica nos animais controles do tratamento. O pré-tratamento com Nw-nitro-L-arginine methyl ester com a dose de 1 mg/kg determinou redução discreta, mas significativa, na retenção gástrica (52 por cento) nos animais tratados com lipopolissacarídio, em relação ao observado naqueles com pré-tratamento e tratamento com veículo (35,9 por cento). Nos animais pré-tratados com 2,5 e 5 mg/kg de Nw-nitro-L-arginine methyl ester e tratados com lipopolissacarídio, houve aumento significante da retenção gástrica (74,7 por cento e 80,5 por cento, respectivamente) em relação aos seus controles pré-tratados com as mesmas doses...


BACKGROUND: There is evidence that nitric oxide plays a role in the decrease in gastric emptying induced by bacterial lipopolysaccharide. AIM: To evaluate the effect of pretreatment with Nw-nitro-L-arginine methyl to ester, one competitive inhibitor of the nitric oxide syntases, on the gastric emptying delay induced by lipopolysaccharide. MATERIAL AND METHODS: Male Wistar rats, SPF, were used after 24 h fast and 1 h-water withdrawn. The pretreatment was done intravenously with vehicle (saline) or Nw-nitro-L-arginine methyl to ester in the doses of 0.5, 1, 2.5 e 5 mg/kg. After 10 min, the animals were treated iv with lipopolysaccharide (50 mg/kg) or received vehicle (saline). The gastric emptying was evaluated 1 h after the lipopolysaccharide administration. A saline solution containing phenol red was used as the test meal. The gastric emptying was indirectly assessed by the determination of percent gastric retention of the test meal 10 min after orogastric administration. RESULTS: The animals pretreated with vehicle and treatment with lipopolysaccharide have significant rise of the gastric retention (average = 57 percent) in comparison with the controls receiving only vehicle (38.1 percent). The pretreatment with the different doses of Nw-nitro-L-arginine methyl to ester did not modify per se the gastric retention in comparison with the animals pretreated with vehicle. Pretreatment with Nw-nitro-L-arginine methyl to ester with the dose of 1 mg/kg determined a discrete but significant reduction in the gastric retention (52 percent) of animals treated with lipopolysaccharide in comparison with vehicle-pretreated rats. Paradoxically, animals pretreated with 2.5 or 5 mg of Nw-nitro-L-arginine methyl to ester/kg followed by treatment with lipopolysaccharide displayed a significantly higher gastric retention (74.7 percent and 80.5 percent, respectively) as compared to their controls, pretreated with the same doses of the inhibitor and treated with vehicle (40.5 percent and...


Assuntos
Animais , Masculino , Ratos , Inibidores Enzimáticos/administração & dosagem , Esvaziamento Gástrico/efeitos dos fármacos , Lipopolissacarídeos/administração & dosagem , NG-Nitroarginina Metil Éster/administração & dosagem , Óxido Nítrico Sintase/antagonistas & inibidores , Análise de Variância , Modelos Animais de Doenças , Injeções Intraventriculares , Ratos Wistar
11.
Acta Gastroenterol Latinoam ; 36(1): 33-7, 2006 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-16706075

RESUMO

Gastric Emptying (GE) is food transition from the stomach to the upper small intestine. Haemodynamics changes modify gastric emptying and the gastroduodenal motor activity. Myocardial Infarction is a pathological condition in which there are haemodynamics changes. Therefore, the objective of the present investigation was to study the effect of acute myocardial infarction on rat gastric emptying of an isosmotic and inert liquid meal. We conducted a study involving male Wistar rats (varying in body weight from 220 g to 250 g), that were allowed to habituate in a laboratory environment and then divided into 3 groups: group INF, rats in which the myocardial infarction was produced by left anterior coronary artery ligation; group SH, rats in which the myocardial infarction was simulated without ligating the anterior coronary artery; and group NA, rats which were not given any anesthesia or surgical procedures. After group constitution, animals were fasted with access to water ad libitum. 24 hours later, the Gastric Retention (GR) of 1.5 ml/100 g animal weight of a test meal of 0.9% NaCl plus the marker phenol red was evaluated. GE was indirectly evaluated in conscious animals, through determining the percentage of gastric retention (% GR) of a test meal, measured 10 minutes after orogastric infusion. Results of the present study showed that animals from the INF group presented GR (median=48.0%), significantly higher than the NA group (30.6%) and SH group (36.6%). No statistical difference in GR was observed between the SH and NA groups. Infarcted area, expressed in percentages, in animals of the INF group was 51.3+/-4.7% (mean SEM, N=17) which not presented correlation with results of GR of the same group (r=-0.05). From a caloric viewpoint, the results suggested that acute myocardial infarct in rats induce delay of the gastric emptying of an isosmotic and inert liquid meal.


Assuntos
Esvaziamento Gástrico/fisiologia , Infarto do Miocárdio/fisiopatologia , Animais , Trânsito Gastrointestinal/fisiologia , Masculino , Ratos , Ratos Wistar
12.
Acta gastroenterol. latinoam ; 36(1): 33-37, mar. 2006. ilus
Artigo em Espanhol | LILACS | ID: lil-442381

RESUMO

El vaciamiento gástrico (VG) es la transferencia del contenido gástrico al intestino delgado. Las alteracioneshemodinámicas modifican el VG y la actividad motora gastroduodenal. El infarto del miocardio (IM) es una condición patológica en la que hay alteraciones hemodinámicas. Siendo así, el objetivo de este trabajo fue evaluar el efecto del infarto agudo del miocardio sobre el vaciamiento gástrico de una comida líquida isosmótica e inerte desde el punto de vista calórico (soluciónsalina). Fueron utilizadas ratas Wistar machos, con un peso de 220-250g, adaptados a condiciones de laboratorioy divididos en 3 grupos: grupo INF (N=17), ratas con infarto del miocardio por ligadura de la arteria coronaria descendiente anterior izquierda; grupoSH (N=15), Sham en las que fue simulado el proceso quirúrgico, sin ligadura de la arteria coronaria; grupoNA (N=15), ratas en las que no fue hecho ningún procedimiento de sedación o quirúrgico. Los animales, después de la constitución de los grupos, permanecieron en ayuno recibiendo agua ad libitum. Veinticuatro horas después fue evaluado el VG de 1,5 ml/100g de peso de animal de una comida de prueba (CP) salinamarcada con fenol rojo. El VG fue evaluado indirectamente en los animales despiertos a través de la determinacióndel porcentaje de retención gástrica (RG) de la CP, 10 minutos después de administración de oro gástrico.Los resultados mostraron que los animales del grupo INF presentaron RG (media=48,0%) significativamentemás alta con relación a los animales del grupo NA (30,6%,) y el grupo SH (36,6%). No hubo diferenciaentre animales del grupo SH con relación a los del grupo NA. El área de infarto, expresada en porcentaje,en los animales del grupo INF fue de 51,3±4,7% ( ±SE, N=17) y no presentó correlación con los resultadosde RG del mismo grupo (r=-0,05).


Gastric Emptying (GE) is food transition from the stomach to the upper small intestine. Haemodynamics changes modify gastric emptying and the gastroduodenal motor activity. Myocardial Infarction is a pathological condition in which there are haemodynamics changes. Therefore, the objective of the present investigation was to study the effect of acute myocardial infarction on rat gastric emptying of an isosmotic and inert liquid meal. We conducted a study involving male Wistar rats (varying in body weight from 220 g to 250 g), that were allowed to habituate in a laboratory environment and then divided into 3 groups: group INF, rats in which the myocardial infarction was produced by left anterior coronary artery ligation; group SH, rats in which the myocardial infarction was simulated without ligating the anterior coronary artery; and group NA, rats which were not given any anesthesia or surgical procedures. After group constitution, animals were fasted with access to water ad libitum. 24 hours later, the Gastric Retention (GR) of 1.5 ml/100 g animal weight of a test meal of 0.9% NaCl plus the marker phenol red was evaluated. GE was indirectly evaluated in conscious animals, through determining the percentage of gastric retention (% GR) of a test meal, measured 10 minutes after orogastric infusion. Results of the present study showed that animals from the INF group presented GR (median=48.0%), significantly higher than the NA group (30.6%) and SH group (36.6%). No statistical difference in GR was observed between the SH and NA groups. Infarcted area, expressed in percentages, in animals of the INF group was 51.3+/-4.7% (mean SEM, N=17) which not presented correlation with results of GR of the same group (r=-0.05). From a caloric viewpoint, the results suggested that acute myocardial infarct in rats induce delay of the gastric emptying of an isosmotic and inert liquid meal.


Assuntos
Animais , Masculino , Ratos , Esvaziamento Gástrico/fisiologia , Infarto do Miocárdio/fisiopatologia , Ratos Wistar , Trânsito Gastrointestinal/fisiologia
13.
Acta gastroenterol. latinoam ; 36(1): 33-37, mar. 2006. ilus
Artigo em Espanhol | BINACIS | ID: bin-119489

RESUMO

El vaciamiento gástrico (VG) es la transferencia del contenido gástrico al intestino delgado. Las alteracioneshemodinámicas modifican el VG y la actividad motora gastroduodenal. El infarto del miocardio (IM) es una condición patológica en la que hay alteraciones hemodinámicas. Siendo así, el objetivo de este trabajo fue evaluar el efecto del infarto agudo del miocardio sobre el vaciamiento gástrico de una comida líquida isosmótica e inerte desde el punto de vista calórico (soluciónsalina). Fueron utilizadas ratas Wistar machos, con un peso de 220-250g, adaptados a condiciones de laboratorioy divididos en 3 grupos: grupo INF (N=17), ratas con infarto del miocardio por ligadura de la arteria coronaria descendiente anterior izquierda; grupoSH (N=15), Sham en las que fue simulado el proceso quirúrgico, sin ligadura de la arteria coronaria; grupoNA (N=15), ratas en las que no fue hecho ningún procedimiento de sedación o quirúrgico. Los animales, después de la constitución de los grupos, permanecieron en ayuno recibiendo agua ad libitum. Veinticuatro horas después fue evaluado el VG de 1,5 ml/100g de peso de animal de una comida de prueba (CP) salinamarcada con fenol rojo. El VG fue evaluado indirectamente en los animales despiertos a través de la determinacióndel porcentaje de retención gástrica (RG) de la CP, 10 minutos después de administración de oro gástrico.Los resultados mostraron que los animales del grupo INF presentaron RG (media=48,0%) significativamentemás alta con relación a los animales del grupo NA (30,6%,) y el grupo SH (36,6%). No hubo diferenciaentre animales del grupo SH con relación a los del grupo NA. El área de infarto, expresada en porcentaje,en los animales del grupo INF fue de 51,3±4,7% ( ±SE, N=17) y no presentó correlación con los resultadosde RG del mismo grupo (r=-0,05).(AU)


Gastric Emptying (GE) is food transition from the stomach to the upper small intestine. Haemodynamics changes modify gastric emptying and the gastroduodenal motor activity. Myocardial Infarction is a pathological condition in which there are haemodynamics changes. Therefore, the objective of the present investigation was to study the effect of acute myocardial infarction on rat gastric emptying of an isosmotic and inert liquid meal. We conducted a study involving male Wistar rats (varying in body weight from 220 g to 250 g), that were allowed to habituate in a laboratory environment and then divided into 3 groups: group INF, rats in which the myocardial infarction was produced by left anterior coronary artery ligation; group SH, rats in which the myocardial infarction was simulated without ligating the anterior coronary artery; and group NA, rats which were not given any anesthesia or surgical procedures. After group constitution, animals were fasted with access to water ad libitum. 24 hours later, the Gastric Retention (GR) of 1.5 ml/100 g animal weight of a test meal of 0.9% NaCl plus the marker phenol red was evaluated. GE was indirectly evaluated in conscious animals, through determining the percentage of gastric retention (% GR) of a test meal, measured 10 minutes after orogastric infusion. Results of the present study showed that animals from the INF group presented GR (median=48.0%), significantly higher than the NA group (30.6%) and SH group (36.6%). No statistical difference in GR was observed between the SH and NA groups. Infarcted area, expressed in percentages, in animals of the INF group was 51.3+/-4.7% (mean SEM, N=17) which not presented correlation with results of GR of the same group (r=-0.05). From a caloric viewpoint, the results suggested that acute myocardial infarct in rats induce delay of the gastric emptying of an isosmotic and inert liquid meal.(AU)


Assuntos
Animais , Masculino , Ratos , Esvaziamento Gástrico/fisiologia , Infarto do Miocárdio/fisiopatologia , Trânsito Gastrointestinal/fisiologia , Ratos Wistar
14.
Acta gastroenterol. latinoam ; 36(1): 33-37, mar. 2006. ilus
Artigo em Espanhol | BINACIS | ID: bin-123357

RESUMO

El vaciamiento gástrico (VG) es la transferencia del contenido gástrico al intestino delgado. Las alteracioneshemodinámicas modifican el VG y la actividad motora gastroduodenal. El infarto del miocardio (IM) es una condición patológica en la que hay alteraciones hemodinámicas. Siendo así, el objetivo de este trabajo fue evaluar el efecto del infarto agudo del miocardio sobre el vaciamiento gástrico de una comida líquida isosmótica e inerte desde el punto de vista calórico (soluciónsalina). Fueron utilizadas ratas Wistar machos, con un peso de 220-250g, adaptados a condiciones de laboratorioy divididos en 3 grupos: grupo INF (N=17), ratas con infarto del miocardio por ligadura de la arteria coronaria descendiente anterior izquierda; grupoSH (N=15), Sham en las que fue simulado el proceso quirúrgico, sin ligadura de la arteria coronaria; grupoNA (N=15), ratas en las que no fue hecho ningún procedimiento de sedación o quirúrgico. Los animales, después de la constitución de los grupos, permanecieron en ayuno recibiendo agua ad libitum. Veinticuatro horas después fue evaluado el VG de 1,5 ml/100g de peso de animal de una comida de prueba (CP) salinamarcada con fenol rojo. El VG fue evaluado indirectamente en los animales despiertos a través de la determinacióndel porcentaje de retención gástrica (RG) de la CP, 10 minutos después de administración de oro gástrico.Los resultados mostraron que los animales del grupo INF presentaron RG (media=48,0%) significativamentemás alta con relación a los animales del grupo NA (30,6%,) y el grupo SH (36,6%). No hubo diferenciaentre animales del grupo SH con relación a los del grupo NA. El área de infarto, expresada en porcentaje,en los animales del grupo INF fue de 51,3±4,7% ( ±SE, N=17) y no presentó correlación con los resultadosde RG del mismo grupo (r=-0,05).(AU)


Gastric Emptying (GE) is food transition from the stomach to the upper small intestine. Haemodynamics changes modify gastric emptying and the gastroduodenal motor activity. Myocardial Infarction is a pathological condition in which there are haemodynamics changes. Therefore, the objective of the present investigation was to study the effect of acute myocardial infarction on rat gastric emptying of an isosmotic and inert liquid meal. We conducted a study involving male Wistar rats (varying in body weight from 220 g to 250 g), that were allowed to habituate in a laboratory environment and then divided into 3 groups: group INF, rats in which the myocardial infarction was produced by left anterior coronary artery ligation; group SH, rats in which the myocardial infarction was simulated without ligating the anterior coronary artery; and group NA, rats which were not given any anesthesia or surgical procedures. After group constitution, animals were fasted with access to water ad libitum. 24 hours later, the Gastric Retention (GR) of 1.5 ml/100 g animal weight of a test meal of 0.9% NaCl plus the marker phenol red was evaluated. GE was indirectly evaluated in conscious animals, through determining the percentage of gastric retention (% GR) of a test meal, measured 10 minutes after orogastric infusion. Results of the present study showed that animals from the INF group presented GR (median=48.0%), significantly higher than the NA group (30.6%) and SH group (36.6%). No statistical difference in GR was observed between the SH and NA groups. Infarcted area, expressed in percentages, in animals of the INF group was 51.3+/-4.7% (mean SEM, N=17) which not presented correlation with results of GR of the same group (r=-0.05). From a caloric viewpoint, the results suggested that acute myocardial infarct in rats induce delay of the gastric emptying of an isosmotic and inert liquid meal.(AU)


Assuntos
Animais , Masculino , Ratos , Esvaziamento Gástrico/fisiologia , Infarto do Miocárdio/fisiopatologia , Trânsito Gastrointestinal/fisiologia , Ratos Wistar
15.
Acta gastroenterol. latinoam ; 36(1): 33-7, 2006 Mar.
Artigo em Espanhol | BINACIS | ID: bin-38153

RESUMO

Gastric Emptying (GE) is food transition from the stomach to the upper small intestine. Haemodynamics changes modify gastric emptying and the gastroduodenal motor activity. Myocardial Infarction is a pathological condition in which there are haemodynamics changes. Therefore, the objective of the present investigation was to study the effect of acute myocardial infarction on rat gastric emptying of an isosmotic and inert liquid meal. We conducted a study involving male Wistar rats (varying in body weight from 220 g to 250 g), that were allowed to habituate in a laboratory environment and then divided into 3 groups: group INF, rats in which the myocardial infarction was produced by left anterior coronary artery ligation; group SH, rats in which the myocardial infarction was simulated without ligating the anterior coronary artery; and group NA, rats which were not given any anesthesia or surgical procedures. After group constitution, animals were fasted with access to water ad libitum. 24 hours later, the Gastric Retention (GR) of 1.5 ml/100 g animal weight of a test meal of 0.9


NaCl plus the marker phenol red was evaluated. GE was indirectly evaluated in conscious animals, through determining the percentage of gastric retention (


GR) of a test meal, measured 10 minutes after orogastric infusion. Results of the present study showed that animals from the INF group presented GR (median=48.0


), significantly higher than the NA group (30.6


) and SH group (36.6


). No statistical difference in GR was observed between the SH and NA groups. Infarcted area, expressed in percentages, in animals of the INF group was 51.3+/-4.7


(mean SEM, N=17) which not presented correlation with results of GR of the same group (r=-0.05). From a caloric viewpoint, the results suggested that acute myocardial infarct in rats induce delay of the gastric emptying of an isosmotic and inert liquid meal.

16.
J Pediatr Gastroenterol Nutr ; 40(3): 339-44, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15735489

RESUMO

OBJECTIVES: The authors hypothesized that acute respiratory distress (ARD) delays gastric emptying. The objective was to test this hypothesis by assessing gastric emptying on the second and seventh days of life in premature infants with ARD resulting from pulmonary disease. METHODS: Thirty-nine newborns with ARD starting on the first day of life were selected and paired with 39 healthy control newborns matched by weight (within 250 g). Gestational age was

Assuntos
Esvaziamento Gástrico/fisiologia , Alimentos Infantis , Recém-Nascido Prematuro , Síndrome do Desconforto Respiratório do Recém-Nascido/fisiopatologia , Doença Aguda , Estudos de Casos e Controles , Ingestão de Alimentos/fisiologia , Feminino , Motilidade Gastrointestinal/fisiologia , Idade Gestacional , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Masculino
17.
Arq. gastroenterol ; 40(2): 104-109, abr.-jun. 2003. ilus
Artigo em Português | LILACS | ID: lil-354028

RESUMO

RACIONAL: O óxido nítrico pode estar envolvido no retardo do esvaziamento gástrico produzido pelo lipopolissacarídio bacteriano. OBJETIVO: Avaliar o efeito do pré-tratamento com a dexametasona, bloqueadora da induçäo do óxido nítrico-sintetase induzida e com o azul de metileno, que bloqueia a guanilato-ciclase, inibe as óxido nítrico-sintetases e inativa o óxido nítrico, sobre o retardo do esvaziamento gástrico determinado pelo lipopolissacarídio em ratos. MATERIAL E MÉTODOS: Foram utilizados ratos Wistar, machos, ''specific patogen free'', após 24 horas de jejum alimentar. No pré-tratamento foram empregadas, via intravenosa, soluções de dexametasona (3 e 6 mg/kg), azul de metileno (2 mg/kg) e veículo estéril. O tratamento constou da administraçäo, via intravenosa, de lipopolissacarídio (50 mig/kg) e veículo. O intervalo entre o pré-tratamento e o tratamento foi de 10 minutos, exceto no estudo com dexametasona 6 mg/kg, que foi de 1 hora. O intervalo entre a administraçäo do lipopolissacarídio e a avaliaçäo do esvaziamento gástrico foi de 1 hora, exceto nos dois estudos com dexametasona 3 mg/kg que foram de 2 e 8 horas. O esvaziamento gástrico foi avaliado, indiretamente, através da determinaçäo da percentagem de retençäo gástrica de soluçäo salina marcada com fenol vermelho. RESULTADOS: Os valores de retençäo gástrica, nos animais pré-tratados com dexametasona ou azul de metileno e tratados com veículo, näo diferiram significativamente dos observados nos que receberam veículo nos dois momentos. Os animais pré-tratados com veículo e tratados com lipopolissacarídio apresentaram valores de retençäo gástrica significativamente mais elevados que nos controles. O pré-tratamento com dexametasona näo interferiu no aumento da retençäo gástrica determinado pelo lipopolissacarídio, nas primeiras 2 horas após administraçäo da endotoxina. Oito horas após a administraçäo da endotoxina, foi observada diminuiçäo significativa da retençäo gástrica nos animais pré-tratados com dexametasona e tratados com lipopolissacarídio em relaçäo aos que receberam veículo + lipopolissacarídio. O mesmo fenômeno foi observado nos animais pré-tratados com azul de metileno e tratados com lipopolissacarídio. CONCLUSÄO: Os resultados sugerem o envolvimento do óxido nítrico no efeito do lipopolissacarídio sobre o esvaziamento gástrico em ratos


Assuntos
Animais , Masculino , Ratos , Dexametasona , Esvaziamento Gástrico , Lipopolissacarídeos , Azul de Metileno , Óxido Nítrico Sintase , Esvaziamento Gástrico , Óxido Nítrico , Ratos Wistar
18.
Arq Gastroenterol ; 40(2): 104-9, 2003.
Artigo em Português | MEDLINE | ID: mdl-14762480

RESUMO

BACKGROUND: The nitric oxide might be a putative mediator of the decrease in gastric emptying induced by bacterial lipopolysaccharide in rats. AIM: For that, we evaluated the effect of the pretreatment intravenous with dexamethasone and methylene blue in the retardation process of gastric emptying induced by intravenous application of lipopolysaccharide in rats. Dexamethasone has been shown to inhibit the induction of NOS II (induced NO-synthase) while the methylene blue, that blocks the soluble guanylyl cyclase, inhibits nitric oxide synthases and, in addition, inactivates nitric oxide directly. MATERIAL AND METHODS: Male Wistar rats, specific patogenic free, were used after a 24 hour fast and 1 hour-water withdrawn. The pretreatment was performed using dexamethasone solutions (3 and 6 mg/kg), methylene blue (2 mg/kg) or sterile vehicle. The treatment consisted in the application of lipopolysaccharide (50 mug/kg) or vehicle. The time period between the pretreatment and treatment was 10 minutes, excluding the study with dexamethasone 6 mg/kg that was 1 hour. The gastric emptying was evaluated 1 hour after the lipopolysaccharide application, except for two studies with dexamethasone 3 mg/kg in which the time periods were 2 and 8 hours. A saline solution containing phenol red was used as the test meal. The gastric emptying was determined by measuring gastric retention 10 minutes after the orogastric infusion of the test meal. RESULTS: The pretreatment with dexamethasone or methylene blue and treatment with vehicle did not have effect in the gastric emptying comparing to the control group. We found that pretreatment with dexamethasone in the studies for 1 hour and 2 hours did not interfere in the retardation of the gastric emptying produced by endotoxin. Nevertheless, in the eighth period study with this drug there was a significant reduction of gastric retention in the endotoxin-treated animals in relation to the unpretreated ones. Meanwhile, the pretreatment with the methylene blue completely blocked the action of endotoxin on the gastric emptying in rats. CONCLUSION: These results suggest a possible involvement of nitric oxide on the effect of lipopolysaccharide in rat gastric emptying.


Assuntos
Dexametasona/farmacologia , Esvaziamento Gástrico/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Azul de Metileno/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Animais , Esvaziamento Gástrico/fisiologia , Masculino , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/fisiologia , Óxido Nítrico Sintase Tipo II , Ratos , Ratos Wistar
19.
Arq. gastroenterol ; 36(1): 42-8, jan.-mar. 1999. graf
Artigo em Português | LILACS | ID: lil-240263

RESUMO

Numa primeira etapa deste estudo, foram determinadas, em ratos adultos, as retenções gástricas de soluções aquosas de lactose, sacarose e maltose, todas na concentração a 10 por cento e da associação combinada entre dois desses açúcares mantendo-se a densidade energética da solução e, numa segunda etapa, as retenções gástricas de leite de vaca integral sem adição e acrescido de sacarose 5 por cento ou maltose 5 por cento. Nas etapas 1 e 2 foram utilizados, respectivamente, 48 e 72 ratos Wistar machos, divididos eqüitativamente em subgrupos, de acordo com a refeição de prova utilizada, empregando-se o volume de 2 mL/100 g de peso. As soluções de açúcares foram marcadas com fenol vermelho (6 mg/dL) e os leites foram marcados com PEG 4000 (2 g/dL). As retenções gástricas foram determinadas calculando-se a quntidade de marcador retido no estômago. Os resultados mostram que a maltose apresentou retenções gástricas significativamente maiores que a da lactose ou sacarose, quando empregadas em soluções isoladas, e que este efeito da maltose manteve-se quando associada a cada um dos outros dois dissacarídios. Quanto às retenções gástricas do leite sem adição de açúcar e com acréscimo de sacarose ou maltose, os resultados não evidenciam diferença significativa ao tempo de 15 minutos. Ao tempo de 30 minutos, as retenções gástricas de leite de vaca com adição de maltose 5 por cento foram significativamente maiores que a de leite sem acréscimo de açúcar. Na avaliação de 45 minutos, foi constatada uma retenção gástrica significativamente maior de leite de vaca com sacarose 5 por cento que de leite de vaca sem adição de açúcar. Os resultados obtidos permitem concluir que a maltose em solução aquosa apresenta esvaziamento gástrico mais lento que soluções de lactose ou sacarose em composição isoenergética, e que o seu efeito mantém-se mesmo quando é associada a qualquer dos outros dois dissacarídeos numa mesma solução ou quando acrescentada ao leite de vaca.


Assuntos
Animais , Masculino , Ratos , Carboidratos , Esvaziamento Gástrico , Leite , Lactose , Maltose , Ratos Wistar , Soluções , Sacarose
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