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1.
J Dairy Sci ; 102(11): 10483-10499, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31495613

RESUMO

The aims of this work were to determine the effect of upland origin on milk composition when comparing similar lowland and upland production system and to highlight the factors responsible for the added value of upland milk from commercial farms. Tanker milk from 55 groups of farms (264 farms in total) in France, Slovakia, and Slovenia was collected twice during the indoor season and 3 times during the outdoor season. The tanker rounds were selected in each country to be balanced according to their origin (lowland or upland) and within upland or lowland groups, according to the forage systems: corn-based or grass-based forage system. At each milk sampling, the production conditions were recorded through on-farm surveys. The milk was analyzed for gross composition, carotenoids, minerals, fatty acids, phenolic compound derivatives, volatile organic compound concentrations, and color. The milk from upland and lowland areas differed in their contents of a few constituents. Upland milk was richer in not identified (n.i.) retention time (Rt) 13,59, 4-methylpentylbenzene, 1-methyl-2-n-hexylbenzene, and ß-caryophyllene than lowland milk. These differences could be most likely attributable to the utilization of highly diversified and extensively managed semi-natural grasslands. The higher forbs content of upland pastures could be related as well to the richness in C18:3n-3, CLA cis-9,trans-11, MUFA, and PUFA we observed in upland compared with lowland milk during the outdoor season. In contrast, grazing on lowland pastures rich in grasses gave a yellower milk that was richer in ß-carotene. Out of the few compounds showing a significant effect of origin or its interaction, most of the milk constituents were unaffected by the origin at all. However, almost all milk constituents differed according to the forage system and the season, and the differences observed between seasons can be attributed to differences in the cow diet composition.


Assuntos
Ração Animal/classificação , Bovinos/fisiologia , Dieta/veterinária , Leite/química , Altitude , Análise de Variância , Ração Animal/análise , Animais , Carotenoides/análise , Ácidos Graxos , Feminino , França , Lactação , Poaceae , Estações do Ano , Eslováquia , Eslovênia , Zea mays
2.
J Dairy Sci ; 98(3): 1539-51, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25529425

RESUMO

The aims of this work were to elucidate the potential of using milk fatty acid (FA) concentration to predict cow diet composition and altitude of bulk milk collected in 10 different European countries and to authenticate cow-feeding systems and altitude of the production area using a data set of 1,248 bulk cow milk samples and associated farm records. The predictions based on FA for cow diet composition were excellent for the proportions of fresh herbage [coefficient of determination (R2)=0.81], good for hay, total herbage-derived forages, and total preserved forages (R2>0.73), intermediate for corn silage and grass silage (R2>0.62), and poor for concentrates (R2<0.51) in the cow diet. Milk samples were assigned to groups according to feeding system, level of concentrate supplementation, and altitude origin. Milk FA composition successfully authenticated cow-feeding systems dominated by a main forage (>93% of samples correctly classified), but the presence of mixed diets reduced the discrimination. Altitude prediction reliability was intermediate (R2<0.62). Milk FA composition was not able to authenticate concentrate supplementation level in the diet (<58% of samples correctly classified). Similarly, the altitude origin was not successfully authenticated by milk FA composition (<76% of samples correctly classified). The potential of milk FA composition to authenticate cow feeding was confirmed using a data set representative of the diversity of European production conditions.


Assuntos
Dieta/veterinária , Ácidos Graxos/análise , Leite/química , Silagem/análise , Altitude , Animais , Bovinos , Suplementos Nutricionais , Europa (Continente) , Poaceae , Reprodutibilidade dos Testes , Zea mays
3.
J Dairy Sci ; 96(7): 4197-211, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23664341

RESUMO

The aim of this study was to predict the fatty acid (FA) composition of bulk milk using data describing farming practices collected via on-farm surveys. The FA composition of 1,248 bulk cow milk samples and the related farming practices were collected from 20 experiments led in 10 different European countries at 44°N to 60°N latitude and sea level to 2,000 m altitude. Farming practice-based FA predictions [coefficient of determination (R(2)) >0.50] were good for C16:0, C17:0, saturated FA, polyunsaturated FA, and odd-chain FA, and very good (R(2) ≥0.60) for trans-11 C18:1, trans-10 + trans-11 C18:1, cis-9,trans-11 conjugated linoleic acid, total trans FA, C18:3n-3, n-6:n-3 ratio, and branched-chain FA. Fatty acids were predicted by cow diet composition and by the altitude at which milk was produced, whereas animal-related factors (i.e., lactation stage, breed, milk yield, and proportion of primiparous cows in the herd) were not significant in any of the models. Proportion of fresh herbage in the cow diet was the main predictor, with the highest effect in almost all FA models. However, models built solely on conserved forage-derived samples gave good predictions for odd-chain FA, branched-chain FA, trans-10 C18:1 and C18:3n-3 (R(2) ≥0.46, 0.54, 0.52, and 0.70, respectively). These prediction models could offer farmers a valuable tool to help improve the nutritional quality of the milk they produce.


Assuntos
Agricultura/métodos , Dieta/veterinária , Ácidos Graxos/análise , Leite/química , Altitude , Animais , Bovinos , Europa (Continente) , Ácidos Graxos Insaturados/análise , Feminino , Lactação , Ácidos Linoleicos Conjugados/análise , Valor Nutritivo , Poaceae , Silagem , Zea mays
4.
J Dairy Sci ; 95(10): 5544-51, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22901470

RESUMO

The ability of near-infrared spectroscopy to trace cow feeding systems and farming altitude was tested on 486 bulk milk samples from France and northwestern Italy. Milks were grouped into feeding systems according to the main forage in the diet. Partial least square discriminant analysis correctly classified 95.5, 91.5, and 93.3% of pasture versus maize silage, hay, and fermented herbage feeding systems, respectively. Discrimination was slightly less successful when diets with large proportions of the nondominant forage were included in each group. Near-infrared spectroscopy correctly discriminated no-pasture from pasture milk, even with only 30% of pasture in the diet (5.4% cross-validation error), and the error stabilized when pasture exceeded 70% (2.5% error). Near-infrared spectroscopy did not reliably trace milk geographic origin when the feeding system effect was isolated from the altitude effect. These findings may be usefully exploited for the authentication of dairy products.


Assuntos
Comportamento Alimentar , Leite/química , Altitude , Ração Animal/análise , Animais , Bovinos , Indústria de Laticínios , Dieta/veterinária , Feminino , França , Geografia , Itália , Silagem/análise , Espectroscopia de Luz Próxima ao Infravermelho
5.
J Med Chem ; 51(5): 1111-4, 2008 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-18271517

RESUMO

Highly water-soluble prodrugs 1a- g of anthelmintic benzimidazole carbamates 2a- g were synthesized. These prodrugs combine high aqueous solubility and stability with high lability in the presence of alkaline phosphatases. The veterinary utility of 1a was shown by a pharmacodynamic and pharmacokinetic study performed in swine. Comparable anthelmintic efficacy was observed with prodrug 1a or the parent fenbendazole 2a. The pharmacokinetic results showed that 2a is better absorbed when derived from 1a than when applied as such.


Assuntos
Anti-Helmínticos/síntese química , Benzimidazóis/síntese química , Carbamatos/síntese química , Pró-Fármacos/síntese química , Drogas Veterinárias/síntese química , Administração Oral , Animais , Anti-Helmínticos/farmacocinética , Anti-Helmínticos/farmacologia , Benzimidazóis/farmacocinética , Benzimidazóis/farmacologia , Carbamatos/farmacocinética , Carbamatos/farmacologia , Galinhas , Estabilidade de Medicamentos , Duodeno/metabolismo , Fenbendazol/sangue , Técnicas In Vitro , Mucosa Intestinal/metabolismo , Jejuno/metabolismo , Oesophagostomum/efeitos dos fármacos , Pró-Fármacos/farmacocinética , Pró-Fármacos/farmacologia , Solubilidade , Relação Estrutura-Atividade , Suínos , Drogas Veterinárias/farmacocinética , Drogas Veterinárias/farmacologia , Água
6.
Biochim Biophys Acta ; 1244(1): 30-40, 1995 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-7766666

RESUMO

Using serial lectin-affinity chromatography, glycosidase digestion, and NMR and methylation analysis, the structures of complex N-linked glycan chains (M(r) range 2000-3500) of rat hepatocytes and poorly differentiated chemically transformed Zajdela ascites hepatoma cells were determined and compared. The results revealed considerable differences between the two cell types: (i) hepatoma cells only expressed tri- and/or tetra-antennary complex N-linked glycan chains, whereas hepatocytes displayed large amounts of bi-antennary N-linked structures and smaller amounts of tri-/tetra-antennary structures; (ii) 20% of the glycan chains in hepatoma cells contained a bisecting GlcNAc residue which was beta (1,4)-linked to the beta-mannosyl residue of the core and was not detected in the hepatocytes; (iii) hepatoma cells expressed a high proportion of the fucosylated or not GlNAc beta (1,6) Man alpha 1-->branch, whereas hepatocytes only contained a little of this branch; (iv) hepatoma cells, but not hepatocytes, exhibited a repeating (Gal beta(1,4) GlcNAc beta (1,3)) sequence characteristic of poly-N-acetyllactosaminoglycans. These glycans were capped by both alpha-galactosyl and sialyl residues; (v) The alpha (2,3)/alpha (2,6)-linkage ratio of sialic acid was significantly higher in hepatoma cells (4/1 vs. 2/1 in hepatocytes); (vi) Only hepatocytes expressed an unusual structure in which a sialyl residue was alpha (2,6)-linked to a GlcNAc residue located within a NeuAc alpha (2,3) Gal beta (1,3) GlcNAc branch which was beta (1,4)-linked to Man alpha 1,3-->. The differences between these complex N-linked glycan chains in hepatocytes and hepatoma cells seem to be both quantitative and qualitative, since some glycan structures were only present in one cell type.


Assuntos
Neoplasias Hepáticas Experimentais/química , Fígado/química , Glicoproteínas de Membrana/química , Animais , Sequência de Carboidratos , Cromatografia de Afinidade , Glucosidases/metabolismo , Glicopeptídeos/química , Lectinas , Espectroscopia de Ressonância Magnética , Masculino , Metilação , Dados de Sequência Molecular , Ratos , Ratos Sprague-Dawley
7.
Acta Chir Belg ; 105(1): 104-5, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15790215

RESUMO

Tracheopathia osteoplastica is a benign cartilaginous and osseous metaplasia of the laryngo-tracheobronchial tree diagnosed more commonly in adults over 50 years of age. We report here the case of a 54-year-old man who underwent thyroidectomy for multinodular goiter. Immediately after an uneventful surgery, he developed an acute respiratory failure with radiologic picture of Adult Respiratory Distress Syndrome. Mechanical ventilation was set up again, bronchoscopy with biopsy disclosed a massive tracheobronchial haemorrhage from a tracheopathia osteoplastica. Supportive treatment was successfully provided and the patient resumed to a normal life 14 days after the operation.


Assuntos
Hemorragia/etiologia , Doenças da Laringe/complicações , Insuficiência Respiratória/etiologia , Doenças da Traqueia/complicações , Doença Aguda , Humanos , Doenças da Laringe/patologia , Masculino , Pessoa de Meia-Idade , Doenças da Traqueia/patologia
8.
Acta Chir Belg ; 105(2): 227-8, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15906924

RESUMO

Tracheopathia osteoplastica is a benign cartilaginous and osseous metaplasia of the laryngo-tracheobronchial tree diagnosed more commonly in adults over 50 years of age. We report here the case of a 54-year-old man who underwent thyroidectomy for multinodular goiter. Immediately after an uneventful surgery, he developed an acute respiratory failure with radiologic picture of Adult Respiratory Distress Syndrome. Mechanical ventilation was set up again, bronchoscopy with biopsy disclosed a massive tracheobronchial haemorrhage from a tracheopathia osteoplastica. Supportive treatment was successfully provided and the patient resumed to a normal life 14 days after the operation.


Assuntos
Bócio/cirurgia , Hemotórax/etiologia , Síndrome do Desconforto Respiratório/etiologia , Tireoidectomia/efeitos adversos , Doenças da Traqueia/etiologia , Doenças da Traqueia/patologia , Biópsia por Agulha , Broncoscopia/métodos , Seguimentos , Bócio/patologia , Hemotórax/fisiopatologia , Hemotórax/terapia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/cirurgia , Respiração Artificial , Síndrome do Desconforto Respiratório/fisiopatologia , Síndrome do Desconforto Respiratório/terapia , Medição de Risco , Tireoidectomia/métodos , Doenças da Traqueia/terapia , Resultado do Tratamento
9.
Rev Med Brux ; 26(5): 439-44, 2005.
Artigo em Francês | MEDLINE | ID: mdl-16318097

RESUMO

Peritoneal carcinomatosis (PC) from colorectal cancer is a dreadful situation characterized by a rapid and mortal evolution (median survival of 5 to 7 months amongst the series published in the literature). The classical treatment includes systemic chemotherapy whether or not associated with palliative surgery. Since the early nineties, locoregional treatments combining extensive cytoreductive surgery with intraperitoneal hyperthermic chemotherapy have been developed, affording some patients a cure and yealding a 5-year survival as high as 30 to 40% in some series. However, it is associated with high morbidity and mortality rates.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Apêndice/patologia , Carcinoma/tratamento farmacológico , Carcinoma/secundário , Neoplasias Colorretais/patologia , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Peritoneais/secundário , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma/cirurgia , Terapia Combinada , Humanos , Hipertermia Induzida , Infusões Parenterais , Período Intraoperatório , Cuidados Paliativos , Neoplasias Peritoneais/cirurgia , Análise de Sobrevida , Resultado do Tratamento
10.
Biochimie ; 74(1): 101-8, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1576202

RESUMO

The relationship between cell differentiation/tumorisation and plasma membrane glycoproteins was approached using peanut agglutinin (PNA) a lectin specific for the Gal-beta(1,3)GalNAc sequence and a homologous cell system consisted of normal rat hepatocytes (HyC) and a poorly differentiated hepatoma (ZHC). This work is focused on the molecular nature of PNA receptors. PNA bound strongly to ZHC, but bound very weakly, if at all to hepatocytes. After sialidase treatment this binding was slightly enhanced in ZHC and HyC. The total number of binding sites on ZHC was 9.6 x 10(6)/cell and 1.2 x 10(7)/cell before and after sialidase treatment respectively. In contrast, this number could not be calculated on HyC, even after sialidase treatment. The PNA receptors were isolated and identified from ZHC using affinity chromatography on immobilized PNA and lectin overlay. Two bands were revealed after SDS-PAGE of PNA receptors: a major one with a relative molecular mass of 160 kDa and a minor one of 110 kDa. The latter disappeared after sialidase treatment of ZHC suggesting the possibility that these two bands could be less and more sialylated forms of the PNA receptors, respectively. In contrast no PNA receptors could be detected on HyC. These PNA receptors could be considered O-linked glycoproteins containing the Gal-beta(1,3)GalNAc disaccharide because: i) PNA carbohydrate specificity toward this disaccharide found in this glycoprotein type; ii) their carbohydrate composition with Gal and GalNAc but not man residues; iii) their sensitivity to alkaline treatment; and iv) strong inhibition of PNA binding to ZHC with the Gal-beta(1,3)GalNAc structure. The absence of PNA receptors on HyC appeared to be related to the absence of this glycoprotein containing the disaccharide but not to the change or failure of glycosylation of the polypeptide chain of PNA receptors. The relationship between the presence of PNA receptors and differentiation/tumorisation phenomena as well as the mechanism that induced the expression of these receptors are discussed.


Assuntos
Transformação Celular Neoplásica/metabolismo , Receptores Mitogênicos/isolamento & purificação , Animais , Sequência de Carboidratos , Diferenciação Celular , Radioisótopos do Iodo , Fígado/citologia , Fígado/metabolismo , Dados de Sequência Molecular , Ratos , Ratos Endogâmicos
11.
Biochem Pharmacol ; 48(6): 1163-9, 1994 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-7945410

RESUMO

The mineralocorticoid receptor (MCR) from bovine kidney was purified on an affinity column containing covalently linked polyclonal IgG raised in the rabbit against rat kidney protein purified in the presence of RU 26752 that is specific to the MCR. The immuno-affinity eluate was excluded as a single peak during gel permeation chromatography and could be resolved as a single band of approximately 98 kDa by western blot and gel electrophoresis. Immunohistochemistry revealed MCR-specific staining in both the cortical and glomerular regions of bovine kidney. Interestingly, the purified MCR could not be activated in the presence of the specific ligand RU 26752 whereas binding to DNA-cellulose increased by 100% when crude cytosol was left at room temperature for 45 min. The binding of calcium to the MCR resulted in an increase in the fluorescence signal that could be partially reversed by EDTA. By a calcium-specific fluorescence dye technique, 1.13 nM of ionized Ca2+ was bound per 0.01 nM MCR. The binding of ATP32 to the immunopurified receptor was observed following chromatography on P-10 columns. The fluorescence signal of etheno-ATP was maximally attenuated by the receptor at 1/1 stoichiometry of the ATP-MCR complex. Asparagine-linked complex chain N-glycosylation of the purified MCR was also observed. Analysis by far-UV circular dichroism spectra showed that MCR contains 33% alpha helices and 30% beta sheets, compatible with a relatively flat conformation of the native protein. These data provide experimental proof for the predicted computer simulation regarding the structural features of the steroid receptor superfamily and suggest crosstalk between several protein families.


Assuntos
Rim/metabolismo , Receptores de Mineralocorticoides/isolamento & purificação , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , Bovinos , Dicroísmo Circular , Simulação por Computador , Glicosilação , Estrutura Molecular , Receptores de Mineralocorticoides/química , Receptores de Mineralocorticoides/metabolismo
12.
Regul Pept ; 54(2-3): 409-15, 1994 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-7716274

RESUMO

The chronotropic cardiac effects of neuropeptide Y (NPY) were studied in the conscious dog with chronic atrioventricular block. NPY (0.2-5 micrograms/kg i.v.) produced no effect on atrial cycle length (ACL), and increased ventricular cycle length (VCL) and mean arterial blood pressure (MBP). After atropine, NPY produced no effect on ACL and increased MBP. At 0.2 microgram/kg, it shortened VCL, whereas at 1 and 5 micrograms/kg, it lengthened this parameter. After pindolol, NPY produced no effect on ACL, shortened VCL and increased MBP. These results indicate that in the conscious dog, NPY (0.2-5 microgram/kg i.v.) does not exert any chronotropic effect on the sinoatrial node, most likely because of competition between opposite chronotropic effects and/or absence of specific NPY receptors in the sinoatrial node. They also suggest that the ventricular bradycardic effects produced by NPY result mainly from a reflex withdrawal of beta-adrenergic tone and that its ventricular tachycardic effects result from a direct action of NPY on specific receptors located in the His bundle.


Assuntos
Frequência Cardíaca/efeitos dos fármacos , Neuropeptídeo Y/farmacologia , Receptores de Neuropeptídeo Y/fisiologia , Animais , Atropina/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Cães , Feminino , Masculino , Pindolol/farmacologia
13.
Eur J Pharmacol ; 306(1-3): 93-8, 1996 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-8813620

RESUMO

We studied the cardiac electrophysiological effects of falipamil, a specific bradycardic agent, in conscious dogs, in comparison with those of alinidine. Sinus rate, corrected sinus recovery time, and Wenckebach point were measured in six intact dogs. Atrial rate, ventricular rate, and atrial effective refractory period were measured in six atrioventricular-blocked dogs. In both groups, blood pressure was also monitored. Each dog received, with at least a three-day interval, falipamil (hydrochloride) and alinidine (hydrobromide) in four successive intravenous injections, 30 min apart, at 0.5, 0.5, 1, and 2 mg kg-1. Falipamil increased sinus rate and atrial rate, but decreased ventricular rate, whereas alinidine decreased sinus rate and ventricular rate, but increased atrial rate. Falipamil shortened corrected sinus recovery time and increased Wenckebach point, whereas alinidine lengthened corrected sinus recovery time and decreased Wenckebach point. Falipamil and alinidine increased atrial effective refractory period. Neither falipamil nor alinidine modified mean blood pressure in either group. Overall, these results show that (a) falipamil exhibits effects on the electrical activity of the heart, reflecting the predominant direct vagolytic effect of this drug, (b) alinidine exhibits effects reflecting the marked antiarrhythmic potential of this agent, and (c) thus indicate that two drugs with almost identical specific bradycardic properties can produce quite different electrophysiological effects in the conscious dog.


Assuntos
Fármacos Cardiovasculares/farmacologia , Clonidina/análogos & derivados , Coração/efeitos dos fármacos , Ftalimidas/farmacologia , Animais , Nó Atrioventricular/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Fascículo Atrioventricular/efeitos dos fármacos , Clonidina/farmacologia , Cães , Eletroencefalografia/efeitos dos fármacos , Eletrofisiologia , Feminino , Frequência Cardíaca/efeitos dos fármacos , Isoindóis , Masculino , Nó Sinoatrial/efeitos dos fármacos
14.
Eur J Pharmacol ; 72(2-3): 165-72, 1981 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-7250206

RESUMO

The tachycardia-inducing effects of atropine, N-methylscopolammonium and N-butylscopolammonium were studied in the conscious dog, both in the presence and absence of sympathetic innervation. These effects were compared with the anticholinergic effects of the drugs on the muscarinic cholinoceptors of guinea-pig isolated atria. The order of potency for inhibition of the effects of acetylcholine on the isolated atria was N-methylscopolammonium greater than atropine greater than N-butylscopolammonium. This order was the same for the tachycardia-inducing potencies. Maximal tachycardia with these three drugs was less marked in the absence of sympathetic innervation than in its presence. However, the doses of atropine and of N-butylscopolammonium required to block the effects of vagal influence were greater. Sympathectomy had no effect on the vagolytic potency of N-methylscopolammonium. In the case of atropine and N-methyl-scopolammonium there was good correlation between anticholinergic and tachycardia-inducing potencies. The tachycardiac effects of these compounds can be explained by their anticholinergic effect. The tachycardia-inducing potency of N-butylscopolammonium was greater than its anticholinergic potency.


Assuntos
Coração/efeitos dos fármacos , Parassimpatolíticos/farmacologia , Receptores Colinérgicos/efeitos dos fármacos , Acetilcolina/antagonistas & inibidores , Animais , Atropina/farmacologia , Cães , Feminino , Cobaias , Coração/inervação , Sistema de Condução Cardíaco/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Técnicas In Vitro , Masculino , Miocárdio/citologia , Receptores Muscarínicos/efeitos dos fármacos , Simpatectomia , Nervo Vago/fisiologia
15.
Eur J Pharmacol ; 58(4): 433-41, 1979 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-510377

RESUMO

In the conscious dog, after intravenous injection of 0.2 mg/kg 3H-labelled atropine the progressive decrease of the heart rate was well correlated with the disappearance of atropine from the blood. But, with atropine infusion (0.2 mg/kg/h) the tachycardia decreased progressively in spite of an increase in the blood concentration of atropine. Differences appeared between the normal animals or those pretreated with propranolol or reserpine, and the animals which had undergone bilateral thoracic sympathectomy. In the stellectomized animals atropine induced a smaller but much more lasting cardiac acceleration than under the other experimental conditions. It seems that only peripheral factors are involved in the complex interactions between the adrenergic and cholinergic nervous systems at the sinus node level.


Assuntos
Atropina/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Animais , Atropina/sangue , Cães , Feminino , Masculino , Propranolol/farmacologia , Reserpina/farmacologia , Simpatectomia , Fatores de Tempo , Vagotomia
16.
Eur J Pharmacol ; 432(1): 1-7, 2001 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-11734181

RESUMO

The present study was designed to investigate which subtype of spinal 5-HT receptors were involved in acetaminophen-induced antinociception using the paw-pressure test. Propacetamol (prodrug of acetaminophen, 400 mg/kg, injected intravenously, corresponding to 200 mg/kg of acetaminophen) produced a significant antinociceptive effect in this test. This effect was at least partially inhibited by intrathecal (i.t.) pretreatment with the 5-HT(1B) (penbutolol), 5-HT(2A) (ketanserin), 5-HT(2C) (mesulergine) receptor antagonists, but not by the 5-HT(1A) (N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclohexanecarboxamide trihydrochloride, WAY 100635) and 5-HT(3) (granisetron) receptor antagonists. This profile was very close to that obtained recently with 5-HT, which suggests an implication of 5-HT in the spinal antinociceptive effect of acetaminophen. These results, the lack of binding of acetaminophen to 5-HT receptors and the increase of central 5-HT levels induced by this drug suggest that acetaminophen-induced antinociception could be indirectly mediated by 5-HT.


Assuntos
Acetaminofen/farmacologia , Analgésicos/farmacologia , Receptores de Serotonina/fisiologia , Animais , Ergolinas/farmacologia , Granisetron/farmacologia , Injeções Espinhais , Ketanserina/farmacologia , Masculino , Limiar da Dor/efeitos dos fármacos , Pembutolol/farmacologia , Piperazinas/farmacologia , Piridinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor 5-HT1B de Serotonina , Receptor 5-HT2A de Serotonina , Receptor 5-HT2C de Serotonina , Receptores de Serotonina/efeitos dos fármacos , Receptores 5-HT1 de Serotonina , Receptores 5-HT3 de Serotonina , Antagonistas da Serotonina/farmacologia , Fatores de Tempo , Vocalização Animal/efeitos dos fármacos
17.
Eur J Pharmacol ; 315(2): 171-7, 1996 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-8960881

RESUMO

We studied the cardiac electrophysiological effects of propafenone and its 5-hydroxylated metabolite in conscious dogs. Sinus rate, corrected sinus recovery time and Wenckebach point were measured in 6 intact dogs. Atrial rate, ventricular rate and atrial effective refractory period were measured in 6 atrioventricular-blocked dogs. In both groups, we also determined blood pressure and plasma drug concentrations. Each dog received, with at least an 8-day interval, propafenone (hydrochloride) and 5-hydroxypropafenone (hydrochloride) in 4 successive intravenous injections, 30 min apart, at 0.5, 0.5, 1 and 2 mg kg(-1). Propafenone increased sinus rate and atrial rate more markedly than 5-hydroxypropafenone, and also transiently ventricular rate, whereas 5-hydroxypropafenone decreased it weakly. Propafenone shortened corrected sinus recovery time and increased Wenckebach point at the highest dose only, whereas 5-hydroxypropafenone did not modify corrected sinus recovery time and increased Wenckebach point less markedly than propafenone. Both drugs produced an identical atrial effective refractory period lengthening. Propafenone either increased mean blood pressure (in intact dogs) or decreased it (in atrioventricular-blocked dogs) at the highest dose only, whereas 5-hydroxypropafenone did not produce any effect on this parameter. Overall, these results show that propafenone and 5-hydroxypropafenone exhibit cardiac electrophysiological effects, reflecting (a) direct vagolytic action for both drugs associated with cardiodepressant effects for 5-hydroxypropafenone, and (b) marked atrial antiarrhythmic properties for 5-hydroxypropafenone probably involved in the therapeutic effect of propafenone.


Assuntos
Antiarrítmicos/farmacologia , Coração/efeitos dos fármacos , Coração/fisiologia , Propafenona/análogos & derivados , Propafenona/farmacologia , Animais , Antiarrítmicos/sangue , Cães , Eletrofisiologia , Feminino , Sistema de Condução Cardíaco/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Injeções Intravenosas , Masculino , Propafenona/sangue
18.
Life Sci ; 54(22): PL381-7, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8177003

RESUMO

The cardiac electrophysiological effects of rilmenidine, a novel antihypertensive agent, and clonidine were studied in the conscious dog. Sinus rate, corrected sinus recovery time (CSRT) and Wenckebach point (WP) were measured in seven intact dogs. Atrial rate and atrial effective refractory period (AERP) were measured in six atrioventricular (AV)-blocked dogs with ventricular pacing. In both groups, blood pressure was also monitored. Each dog received with at least a three-day interval rilmenidine as dihydrogen phosphate and clonidine as hydrochloride in four successive intravenous injections, 30 min apart. In intact dogs, rilmenidine was administered at 50, 50, 100 and 200 micrograms/kg and clonidine at 2.5, 2.5, 5 and 10 micrograms/kg. In AV-blocked dogs, doses of rilmenidine were 25, 25, 50 and 100 micrograms/kg, those of clonidine 5, 5, 10 and 20 micrograms/kg. Rilmenidine and clonidine decreased sinus rate and atrial rate from the first dose. In this regard, rilmenidine was respectively 24 and 23 times less potent than clonidine. A lengthening of CSRT was observed at all doses with rilmenidine and at the last three doses with clonidine (ratio: 17) and a lowering of WP at all doses with rilmenidine and clonidine (ratio: 22). A shortening of AERP was also seen with rilmenidine and clonidine from the second dose (ratio: 6). All these effects may at least partly be explained by a cholinergic activation mechanism. In intact dogs both drugs produced a lowering of mean blood pressure (ratio: 17), whereas in AV-blocked dogs, in which ventricular rate was kept constant by pacing, pressure effects were more complex, being the resultant of hypotensive and hypertensive effects, the latter due to alpha vascular stimulation. Taken together, these results indicate that in the conscious dog, rilmenidine and clonidine exert qualitatively identical electrophysiological effects, but with different potency ratios.


Assuntos
Anti-Hipertensivos/farmacologia , Clonidina/farmacologia , Coração/efeitos dos fármacos , Oxazóis/farmacologia , Animais , Função Atrial , Pressão Sanguínea/efeitos dos fármacos , Cães , Eletrocardiografia , Eletrofisiologia , Feminino , Coração/fisiologia , Átrios do Coração/efeitos dos fármacos , Masculino , Rilmenidina , Nó Sinoatrial/efeitos dos fármacos , Nó Sinoatrial/fisiologia
19.
Life Sci ; 50(20): PL161-6, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1579041

RESUMO

The cardiac vagolytic effects of disopyramide and its mono-N-dealkylated metabolite (MND), and their interactions with the cardiac cholinergic system, were assessed using in vivo and in vitro experiments. In chloralose anesthetized dogs, disopyramide phosphate (0.25 mg/kg/min) and MND at equimolar dose (0.173 mg/kg/min) reduced vagal bradycardia. As indicated by the ED80, MND exhibits a vagolytic activity 1.5-2 times less potent than disopyramide. Concomitantly, increases in heart rate and mean blood pressure were observed with disopyramide, whereas with MND only a rise in mean blood pressure occurred. In conscious dogs, where vagal tone is fully expressed, disopyramide and MND increased heart rate and, interestingly, prevented any atropine-induced additional tachycardia, though heart rate was relatively low. Binding studies on rat heart membranes yielded Ki values 2-2.5 times higher for MND than for disopyramide, and demonstrated that neither disopyramide nor MND binding modified the cardiac muscarinic receptor sites. Taken together, these results show that disopyramide exhibits a more potent cardiac vagolytic action than MND, very likely linked to a greater ability to bind to cardiac muscarinic receptors. They also show that disopyramide and MND are very potent in preventing atropine-induced "excess tachycardia", very likely by inhibiting the ionic pacemaker current(s) involved in its genesis.


Assuntos
Disopiramida/farmacologia , Coração/efeitos dos fármacos , Miocárdio/metabolismo , Receptores Colinérgicos/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Disopiramida/metabolismo , Cães , Estimulação Elétrica , Feminino , Frequência Cardíaca/efeitos dos fármacos , Técnicas In Vitro , Masculino , Ratos , Ratos Endogâmicos , Receptores Colinérgicos/metabolismo , Nervo Vago/efeitos dos fármacos , Nervo Vago/fisiologia
20.
Life Sci ; 35(17): 1739-45, 1984 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-6548282

RESUMO

The chronotropic and inotropic effects of muscarinic receptor agonists (Acetylcholine, Arecoline, Carbachol, Furtrethonium) and antagonists (Atropine, N-methyl and N-butyl scopolammonium, pirenzepine) on isolated guinea-pig atria were studied. All had a greater affinity constants for muscarinic receptors as assessed in terms of inotropic effects than in terms of chronotropic effects. This difference, well correlated with the pharmacological effect, suggests the occurrence of cardiac muscarinic receptor subtypes, one mediating heart rate and the other contractile force. The ratio of chronotropic to inotropic potencies for each agent shows that the physiological mediator. Acetylcholine, differentiates best between the two subtypes, while atropine is the least discriminatory.


Assuntos
Frequência Cardíaca/efeitos dos fármacos , Contração Miocárdica/efeitos dos fármacos , Receptores Muscarínicos/metabolismo , Acetilcolina/farmacologia , Animais , Arecolina/farmacologia , Atropina/farmacologia , Benzodiazepinonas/farmacologia , Sítios de Ligação , Brometo de Butilescopolamônio/farmacologia , Carbacol/farmacologia , Feminino , Cobaias , Masculino , Miocárdio/metabolismo , N-Metilescopolamina , Pirenzepina , Compostos de Amônio Quaternário/farmacologia , Derivados da Escopolamina/farmacologia
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