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1.
J Pediatr Gastroenterol Nutr ; 59(6): 725-31, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25079478

RESUMO

OBJECTIVES: In preterm infants, the metabolic responses of gastrointestinal (GI) bacteria to different diets are poorly understood despite the possible effects on GI health. Therefore, we tested the hypothesis that diet influences bacterial metabolism by measuring short-chain fatty acids (SCFAs) in stool samples from very-low-birth-weight (VLBW) preterm infants without GI disorder as surrogate biomarkers of bacterial metabolism. METHODS: Ion chromatography was used to measure fecal SCFAs (acetate, formate, propionate, butyrate, and isobutyrate), lactate, and chloride in fresh stool samples collected from 32 preterm infants (without major congenital anomalies, GI disorders, or a recent history of antibiotic administration and on full feed of either expressed maternal breast milk [EBM; n = 13] or a formula for preterm infants [Similac Special Care Formula; preterm formula, PTF; n = 19]). RESULTS: The mean birth weight was 972 g, the mean gestational age was 27 weeks, and the mean postnatal age at first stool sample was 36 days. When adjusted for gestational age, the stools of EBM infants had higher concentrations (micromoles per gram of stool) of total SCFA (128 vs 68; P = 0.002), acetate (41 vs 13; P = 0.005), propionate (15.1 vs 4.4; P = 0.003), and chloride (21,814 vs 10,652; P = 0.02). Interactions between postnatal age and diet were detected for lactate (P = 0.05), propionate (P = 0.03), and butyrate (P = 0.03). CONCLUSIONS: Diets fed to VLBW preterm infants influence fecal SCFA profiles, and hence the metabolism of the GI bacteria, and potentially the health of preterm infants. The responses of bacterial metabolism to diet are influenced with postnatal age and gestational age at birth.


Assuntos
Trato Gastrointestinal/microbiologia , Fórmulas Infantis , Fenômenos Fisiológicos da Nutrição do Lactente , Recém-Nascido Prematuro/fisiologia , Recém-Nascido de muito Baixo Peso/fisiologia , Leite Humano , Bactérias/metabolismo , Peso ao Nascer , Dieta , Ácidos Graxos Voláteis/análise , Fezes/química , Trato Gastrointestinal/crescimento & desenvolvimento , Idade Gestacional , Humanos , Recém-Nascido , Terapia Intensiva Neonatal , Estudos Prospectivos
2.
J Anim Sci ; 91(10): 4713-29, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23942716

RESUMO

At birth, the newborn mammal undergoes a transition from a sterile uterine environment with a constant nutrient supply, to a microbe-rich environment with intermittent oral intake of complex milk nutrients via the gastrointestinal tract (GIT). These functional challenges partly explain the relatively high morbidity and mortality of neonates. Preterm birth interrupts prenatal organ maturation, including that of the GIT, and increases disease risk. Exemplary is necrotizing enterocolitis (NEC), which is associated closely with GIT immaturity, enteral feeding, and bacterial colonization. Infants with NEC may require resection of the necrotic parts of the intestine, leading to short bowel syndrome (SBS), characterized by reduced digestive capacity, fluid loss, and dependency on parenteral nutrition. This review presents the preterm pig as a translational model in pediatric gastroenterology that has provided new insights into important pediatric diseases such as NEC and SBS. We describe protocols for delivery, care, and handling of preterm pigs, and show how the immature GIT responds to delivery method and different nutritional and therapeutic interventions. The preterm pig may also provide a sensitive model for postnatal adaptation of weak term piglets showing high mortality. Attributes of the preterm pig model include close similarities with preterm infants in body size, organ development, and many clinical features, thereby providing a translational advantage relative to rodent models of GIT immaturity. On the other hand, the need for a sow surgical facility, a piglet intensive care unit, and clinically trained personnel may limit widespread use of preterm pigs. Studies on organ adaptation in preterm pigs help to identify the physiological basis of neonatal survival for hypersensitive newborns and aid in defining the optimal diet and rearing conditions during the critical neonatal period.


Assuntos
Animais Recém-Nascidos , Trato Gastrointestinal/crescimento & desenvolvimento , Recém-Nascido Prematuro/fisiologia , Nascimento Prematuro , Suínos/fisiologia , Animais , Feminino , Trato Gastrointestinal/fisiologia , Humanos , Gravidez
3.
J Anim Sci ; 90 Suppl 4: 290-8, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23365359

RESUMO

Despite clinical research and medical advances, care of the preterm infant remains a clinical challenge, with the immature gastrointestinal (GI) system limiting the types and amounts of nutrients that can be provided enterally to meet energy and nutrient requirements. Progress in understanding the relationship between dietary inputs and the developing GI system after preterm birth has been limited by ethical constraints of using preterm infants as experimental subjects and a lack of relevant animal models. We review development of the GI system of the pig during gestation, the similarities shared with human fetuses, and the responses to dietary stimuli. The GI systems of pigs and humans develop early in gestation, with growth and maturation accelerating during the final weeks prior to birth. As a consequence, deficits in GI digestive capacities are directly related to how early in gestation an infant or pig is delivered, thereby complicating attempts to provide adequate enteral nutrients for growth and development. Pigs differ from humans by being born with low activities of the brush border membrane carbohydrases necessary for hydrolysis of nonlactose carbohydrates. Fetuses of both species have impaired lipid digestion coinciding with lipid malabsorption after preterm birth. Protease activity, although present, may not be adequate and may limit growth potential. Undigested enteral inputs are available to the resident bacteria and the production of metabolites can influence health and nutrition. The preterm pig represents a relevant and translational animal model for understanding GI development and for identifying diet and regulatory factors that stimulate GI growth and maturation after preterm birth and thereby accelerate the transition from parenteral nutrition to full enteral nutrition.


Assuntos
Desenvolvimento Fetal/fisiologia , Trato Gastrointestinal/crescimento & desenvolvimento , Nascimento Prematuro , Suínos/crescimento & desenvolvimento , Animais , Feminino , Gravidez
4.
J Anim Sci ; 89(5): 1506-19, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21239667

RESUMO

Mammalian gastrointestinal (GI) development is guided by genetic determinants established during the evolution of mammals and matched to the natural diet and environment. Coevolution of the host GI tract (GIT) and the resident bacteria has resulted in commensal relationships that are species and even individual specific. The interactions between the host and the GI bacteria are 2-way and of particular importance during the neonatal period, when the GIT needs to adapt rapidly to the external environment, begin processing of oral foods, and acquire the ability to differentiate between and react appropriately to colonizing commensal and potentially pathogenic bacteria. During this crucial period of life, the patterns of gene expression that determine GI structural and functional development are modulated by the bacteria colonizing the previously sterile GIT of fetuses. The types and amounts of dietary inputs after birth influence GI development, species composition, and metabolic characteristics of the resident bacteria, and the interactions that occur between the bacteria and the host. This review provides overviews of the age-related changes in GIT functions, the resident bacteria, and diet, and describes how interactions among these 3 factors influence the health and nutrition of neonates and can have lifelong consequences. Necrotizing enterocolitis is a common GI inflammatory disorder in preterm infants and is provided as an example of interactions that go awry. Other enteric diseases are common in all newborn mammals, and an understanding of the above interactions will enhance efforts to support neonatal health for infants and for farm and companion animals.


Assuntos
Trato Gastrointestinal/microbiologia , Metagenoma/fisiologia , Animais , Animais Recém-Nascidos , Digestão/fisiologia , Trato Gastrointestinal/metabolismo , Humanos , Recém-Nascido , Modelos Animais , Equilíbrio Hidroeletrolítico
5.
Am J Physiol Regul Integr Comp Physiol ; 294(3): R929-38, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18160527

RESUMO

Although preterm birth and formula feeding increase the risk of necrotizing enterocolitis (NEC), the influences of cesarean section (CS) and vaginal delivery (VD) are unknown. Therefore, gut characteristics and NEC incidence and severity were evaluated in preterm pigs (92% gestation) delivered by CS or VD. An initial study showed that newborn CS pigs (n = 6) had decreased gastric acid secretion, absorption of intact proteins, activity of brush-border enzymes and pancreatic hydrolases, plasma cortisol, rectal temperature, and changes in blood chemistry, indicating impaired respiratory function, compared with VD littermates (n = 6). In a second experiment, preterm CS (n = 16) and VD (n = 16) pigs were given total parenteral nutrition (36 h) then fed porcine colostrum (VD-COL, n = 6; CS-COL, n = 6) or infant milk formula (VD-FORM, n = 10; CS-FORM, n = 10) for 2 days. Across delivery, FORM pigs showed significantly higher NEC incidence, tissue proinflammatory cytokines (IFN-gamma and IL-6), Clostridium colonization, and impaired intestinal function, compared with COL pigs. NEC incidence was equal for CS (6/16) and VD (6/16) pigs, CS pigs had decreased bacterial diversity and density, higher villus heights, and increased brush-border enzyme activities (lactase, aminopeptidases) compared with VD pigs. In particular, VD-FORM pigs showed reduced mucosal proportions, reduced lactase and aminopeptidases, and increased proinflammatory cytokine IL-6 compared with CS-FORM (P < 0.06). Despite the initial improvement of intestinal and metabolic functions following VD, gut function, and inflammation were similar, or more negatively affected in VD neonates than CS neonates. Both delivery modes exhibited positive and negative influences on the preterm gut, which may explain the similar NEC incidence.


Assuntos
Cesárea/efeitos adversos , Enterocolite Necrosante/microbiologia , Feto/fisiologia , Intestinos/crescimento & desenvolvimento , Intestinos/microbiologia , Animais , Análise Química do Sangue , Colostro/fisiologia , Citocinas/metabolismo , Dieta , Enterocolite Necrosante/patologia , Ácidos Graxos/metabolismo , Feminino , Determinação da Acidez Gástrica , Mucosa Gástrica/metabolismo , Concentração de Íons de Hidrogênio , Absorção Intestinal/fisiologia , Intestinos/patologia , Microvilosidades/enzimologia , Tamanho do Órgão/fisiologia , Parto/fisiologia , Polimorfismo de Fragmento de Restrição , Gravidez , Suínos
6.
J Pediatr Gastroenterol Nutr ; 43(2): 160-7, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16877979

RESUMO

OBJECTIVES: Parenteral nutrition is a critically important intervention for children with intestinal dysfunctions. However, total parenteral nutrition (TPN) with no enteral feeding is associated with small intestine atrophy and malabsorption, which complicate the transition to enteral nutrition. The objective of the present study was to evaluate the therapeutic potential of the intestinotrophic peptide glucagon-like peptide 2 (GLP-2), which reduces TPN-associated atrophy and maintains nutrient absorption in adult rats, for preventing nutrient malabsorption in neonates receiving TPN. METHODS: Term pigs obtained by cesarean delivery received from birth TPN alone (TPN; n = 7) or TPN with GLP-2 (25 nmol . kg(-1) . d(-1); GLP-2; n = 8) or were fed sow milk enterally (n = 7). The small intestine was removed on postnatal day 6 to measure morphological responses and absorption of glucose, leucine, lysine and proline by intact tissues and brush border membrane vesicles and to quantify the abundances of mRNA and protein for enterocyte glucose transporters (SGLT-1 and GLUT2). RESULTS: Relative to TPN alone, administration of GLP-2 resulted in small intestines that were larger (P < 0.01), had greater abundances of mRNA and protein for SGLT-1, but not for GLUT2, and had higher capacities to absorb nutrients (P < 0.01). Moreover, the intestines of GLP-2 pigs were comparable in size and absorptive capacities with those of pigs fed sow milk enterally. CONCLUSIONS: Providing GLP-2 to neonates receiving TPN prevents small intestine atrophy, results in small intestine absorptive capacities that are comparable to when nutrients are provided enterally and may accelerate the transition from TPN to enteral nutrition.


Assuntos
Peptídeos Semelhantes ao Glucagon/farmacologia , Absorção Intestinal/efeitos dos fármacos , Intestino Delgado/efeitos dos fármacos , Síndromes de Malabsorção/prevenção & controle , Nutrição Parenteral Total , Animais , Animais Recém-Nascidos , DNA/biossíntese , Modelos Animais de Doenças , Peptídeo 2 Semelhante ao Glucagon , Peptídeos Semelhantes ao Glucagon/uso terapêutico , Absorção Intestinal/fisiologia , Intestino Delgado/crescimento & desenvolvimento , Intestino Delgado/metabolismo , Distribuição Aleatória , Transportador 1 de Glucose-Sódio/metabolismo , Suínos , Distribuição Tecidual
7.
J Vet Intern Med ; 20(2): 388-94, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16594599

RESUMO

A urine sucrose test has recently been reported to be a reliable method of detecting gastric ulcers in horses; however, technical difficulties associated with urine collection have limited the practical value of the test. The objective of this pilot study was to determine whether gastric sucrose permeability, as evaluated by serum sucrose concentration, could be used to detect gastric mucosal injury in horses. Twelve adult horses with naturally acquired gastric ulceration were studied. After a 20-hour nonfeeding period, each horse was dosed with 250 g of sucrose via nasogastric intubation. Blood samples were collected at 0, 15, 30, 45, 60, and 90 minutes, and horses underwent gastroscopy 4 hours later. The severity of gastric ulceration in each horse was defined by means of a 4-point ulcer-scoring system, and the relationship with serum sucrose concentration was analyzed by means of a linear mixed-effects model. Serum sucrose concentration was measured by liquid chromatography operating in tandem with electrospray mass spectrometry. After nasogastric administration of table sugar, horses with moderate to severe gastric ulceration had significant increase in serum sucrose concentration at 30, 45, 60, and 90 minutes, relative to earlier times (P < .05). Peak sucrose concentration was observed at 45 minutes, and was correlated with ulcer severity (Spearman's rank correlation coefficient = 0.898, P < .05). These data indicate that determination of sucrose concentration in equine serum may be a useful test for identifying horses with endoscopically visible gastric ulceration and has potential use as a noninvasive method for screening and monitoring horses engaged in racing training and other performance-related disciplines.


Assuntos
Mucosa Gástrica/fisiopatologia , Doenças dos Cavalos/sangue , Doenças dos Cavalos/fisiopatologia , Cavalos/sangue , Úlcera Gástrica/veterinária , Sacarose/sangue , Animais , Feminino , Doenças dos Cavalos/diagnóstico , Masculino , Permeabilidade , Úlcera Gástrica/diagnóstico , Úlcera Gástrica/fisiopatologia , Sacarose/administração & dosagem
8.
Am J Physiol Gastrointest Liver Physiol ; 290(2): G293-300, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16166344

RESUMO

Premature infants receiving chronic total parenteral nutrition (TPN) due to feeding intolerance develop intestinal atrophy and reduced nutrient absorption. Although providing the intestinal trophic hormone glucagon-like peptide-2 (GLP-2) during chronic TPN improves intestinal growth and morphology, it is uncertain whether GLP-2 enhances absorptive function. We placed catheters in the carotid artery, jugular and portal veins, duodenum, and a portal vein flow probe in piglets before providing either enteral formula (ENT), TPN or a coinfusion of TPN plus GLP-2 for 6 days. On postoperative day 7, all piglets were fed enterally and digestive functions were evaluated in vivo using dual infusion of enteral ((13)C) and intravenous ((2)H) glucose, in vitro by measuring mucosal lactase activity and rates of apical glucose transport, and by assessing the abundances of sodium glucose transporter-1 (SGLT-1) and glucose transporter-2 (GLUT2). Both ENT and GLP-2 pigs had larger intestine weights, longer villi, and higher lactose digestive capacity and in vivo net glucose and galactose absorption compared with TPN alone. These endpoints were similar in ENT and GLP-2 pigs except for a lower intestinal weight and net glucose absorption in GLP-2 compared with ENT pigs. The enhanced hexose absorption in GLP-2 compared with TPN pigs corresponded with higher lactose digestive and apical glucose transport capacities, increased abundance of SGLT-1, but not GLUT-2, and lower intestinal metabolism of [(13)C]glucose to [(13)C]lactate. Our findings indicate that GLP-2 treatment during chronic TPN maintains intestinal structure and lactose digestive and hexose absorptive capacities, reduces intestinal hexose metabolism, and may facilitate the transition to enteral feeding in TPN-fed infants.


Assuntos
Peptídeos Semelhantes ao Glucagon/uso terapêutico , Hexoses/metabolismo , Síndromes de Malabsorção/prevenção & controle , Nutrição Parenteral Total/efeitos adversos , Algoritmos , Animais , Animais Recém-Nascidos , Dióxido de Carbono/metabolismo , DNA/biossíntese , DNA/genética , Peptídeo 2 Semelhante ao Glucagon , Glucose/administração & dosagem , Glucose/metabolismo , Transportador de Glucose Tipo 2/metabolismo , Íleo/metabolismo , Infusões Intravenosas , Jejuno/metabolismo , Cinética , Lactase/metabolismo , Consumo de Oxigênio/fisiologia , Transportador 1 de Glucose-Sódio/metabolismo , Suínos , Distribuição Tecidual
9.
J Comp Physiol B ; 176(3): 233-41, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16344990

RESUMO

Glucocorticoids from endogenous and exogenous sources accelerate maturation of brush-border membrane (BBM) hydrolases in omnivorous laboratory rodents and pigs. Less is known for carnivores, and whether the route of administration (oral or systemic) has an influence. The present study examined the influence of administering cortisol (hydrocortisone succinate, 5 mg/kg-day) to mink during postnatal week 4, just prior to weaning, on small intestine glucose and amino acid (aspartate, leucine, lysine, methionine, proline) absorption and on the activities of BBM disaccharidases and peptidases. Kits treated with cortisol were smaller (P<0.05), but had small intestines that were proportionally larger (P<0.05 for length and mass per kg body weight, but not for mucosal mass) than control kits with higher rates of absorption for most nutrients, except leucine, and increased activities of most BBM hydrolases, except lactase. As a consequence, cortisol increased hydrolytic and absorptive capacities of the entire small intestine, with the responses more pronounced when the cortisol was given orally. These findings indicate administration of cortisol stimulates growth of the developing mink small intestine, but does not accelerate the postnatal declines in nutrient transport, and may be a dam-to-kit signal that prepares suckling mink to digest and absorb the adult diet.


Assuntos
Hidrocortisona/farmacologia , Hidrolases/metabolismo , Intestinos/efeitos dos fármacos , Intestinos/enzimologia , Vison/crescimento & desenvolvimento , Aminoácidos/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Proteínas de Transporte/metabolismo , Polaridade Celular , Glucose/metabolismo , Vison/metabolismo , Desmame
10.
J Comp Physiol B ; 173(1): 61-7, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12592444

RESUMO

Pharmacokinetics for one growth hormone secretogogue (NNC 26-0722), but not for another (NN703), differ between dogs in estrus or anestrus. We examined if the differences could be mimicked by administering estradiol during anestrus and if there was a relationship with rates of small intestine absorption. Pharmacokinetics for oral doses of NN703 (1.0-1.6 mg kg(-1)) did not differ among dogs in estrus, anestrus, or anestrus and given estradiol for 1 week (days 1, 3, and 6; 40 micro g kg(-1)), whereas plasma concentrations of NNC 26-0722 increased from undetectable in untreated, anestrus dogs to several hundred nanograms per milliliter in dogs given estradiol, with maximal concentrations measured 5 min after oral dosage. Estradiol treatment increased small intestinal absorption of NNC 26-0722 by 100% (P<0.05), but did not increase absorption of NN703, and caused a 64% increase in carrier-mediated glucose transport at 50 mmol l(-1) (P<0.05) due to increased densities of transporters. These findings indicate estrus and estradiol enhance absorptive functions of the dog proximal small intestine and can affect pharmacokinetics for some orally administered drugs.


Assuntos
Anestro/metabolismo , Dipeptídeos/farmacocinética , Estradiol/farmacologia , Glucose/farmacocinética , Absorção Intestinal/fisiologia , Intestino Delgado/metabolismo , Simportadores , Administração Oral , Animais , Proteínas de Transporte/metabolismo , Cães , Feminino , Absorção Intestinal/efeitos dos fármacos , Glicoproteínas de Membrana/metabolismo , Proteínas de Transporte de Monossacarídeos/metabolismo , Transportador 1 de Peptídeos , Transportador 1 de Glucose-Sódio
12.
Br J Nutr ; 87 Suppl 2: S231-9, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12088523

RESUMO

Animals are constantly exposed to a diversity of health challenges and the gastrointestinal tract (GIT) is a major, if not the principal, site of exposure. Animal models and a limited number of human clinical studies have shown that the assemblages and metabolic activities of the resident bacteria are important determinants of the effectiveness of the various host defense mechanisms and thereby influence the ability of animals to respond to health challenges. The assemblages of bacteria resident in the GIT provide a first line of defense that can exclude invading pathogens, reduce the proliferation of opportunistic pathogens already resident in the GIT, and reduce the availability, carcinogenicity, or toxicity of noxious chemicals. The mucosa of the GIT is a second, multilayered line of defense that includes the mucous and other secretions, the epithelial cells, and immune-associated cells scattered within and under the epithelium. The final line of defense contends with pathogens or noxious chemicals that transcend the mucosal barrier and enter the host and consists of the innate and acquired components of the systemic immune system and the xenobiotic metabolizing enzymes. The lactic acid producing bacteria (LAB) are considered to be immunomodulatory and directly or indirectly influence the GIT and systemic defense functions. Corresponding with this, supplementing the diet with inulin, oligofructose, or other nondigestible oligosaccharides that increase the densities and metabolic capacities of the LAB enhances defense mechanisms of the host, increases resistance to various health challenges, and accelerates recovery of the GIT after disturbances.


Assuntos
Fibras na Dieta/administração & dosagem , Intestinos/imunologia , Intestinos/microbiologia , Lactobacillus/metabolismo , Oligossacarídeos/administração & dosagem , Animais , Infecções Bacterianas/imunologia , Infecções Bacterianas/microbiologia , Fibras na Dieta/metabolismo , Imunoglobulinas/imunologia , Inulina/administração & dosagem , Inulina/metabolismo , Linfócitos/imunologia , Modelos Animais , Oligossacarídeos/metabolismo , Toxinas Biológicas/metabolismo
13.
Am J Physiol Regul Integr Comp Physiol ; 280(1): R241-7, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11124157

RESUMO

Amino acids originating from the diet are the principal metabolic fuels for the small intestine, and although the developing intestine is exposed to dramatic changes in the types and amounts of protein, there is little known about rates of amino acid absorption across the apical membrane during development. Therefore, rates of absorption were measured for five amino acids that are substrates for the acidic (aspartate), basic (lysine), neutral (leucine and methionine), and imino (proline) amino acid carriers using intact tissues from the proximal, mid-, and distal small intestines of pigs ranging in age from 90% of gestation to 42 days after birth (12 days after weaning). Rates of absorption (sum of carrier-mediated and apparent diffusion) were highest at birth (except for proline) and declined by an average of 30% during the first 24 h of suckling. There were continuing declines for leucine, methionine, and proline but not for aspartate and lysine. Due to rapid growth of the intestine, absorption capacities for all amino acids increased faster than predicted from gains in metabolic mass. Regional differences for rates of absorption were not detected until after birth, and only for aspartate and proline. Maximum rates of saturable absorption (nmol. min(-1). mg tissue(-1)) by the midintestine increased during the last 10% of gestation, were highest at birth, and then declined. The contribution of apparent diffusion to amino acid absorption was lowest at birth, then increased after onset of suckling.


Assuntos
Aminoácidos/farmacocinética , Absorção Intestinal/fisiologia , Intestino Delgado/crescimento & desenvolvimento , Intestino Delgado/metabolismo , Fatores Etários , Animais , Animais Lactentes , Ácido Aspártico/farmacocinética , Feminino , Leucina/farmacocinética , Lisina/farmacocinética , Metionina/farmacocinética , Tamanho do Órgão , Gravidez , Prolina/farmacocinética , Suínos
14.
Am J Physiol Gastrointest Liver Physiol ; 279(6): G1249-56, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11093948

RESUMO

We wished to determine whether exogenous glucagon-like peptide (GLP)-2 infusion stimulates intestinal growth in parenterally fed immature pigs. Piglets (106-108 days gestation) were given parenteral nutrient infusion (TPN), TPN + human GLP-2 (25 nmol. kg(-1). day(-1)), or sow's milk enterally (ENT) for 6 days. Intestinal protein synthesis was then measured in vivo after a bolus dose of [1-(13)C]phenylalanine, and degradation was calculated from the difference between protein accretion and synthesis. Crypt cell proliferation and apoptosis were measured in situ by 5-bromodeoxyuridine (BrdU) and terminal dUTP nick-end labeling (TUNEL), respectively. Intestinal protein and DNA accretion rates and villus heights were similar in GLP-2 and ENT pigs, and both were higher (P < 0.05) than in TPN pigs. GLP-2 decreased fractional protein degradation rate, whereas ENT increased fractional protein synthesis rate compared with TPN pigs. Percentage of TUNEL-positive cells in GLP-2 and ENT groups was 48 and 64% lower, respectively, than in TPN group (P < 0.05). However, ENT, but not GLP-2, increased percentage of BrdU-positive crypt cells above that in TPN piglets. We conclude that GLP-2 increases intestinal growth in premature, TPN-fed pigs by decreasing proteolysis and apoptosis, whereas enteral nutrition acts via increased protein synthesis and cell proliferation and decreased apoptosis.


Assuntos
Apoptose , Proteínas Alimentares/metabolismo , Intestinos/crescimento & desenvolvimento , Nutrição Parenteral Total , Peptídeos/farmacologia , Animais , Animais Recém-Nascidos , Nutrição Enteral , Feminino , Mucosa Gástrica/metabolismo , Peptídeo 2 Semelhante ao Glucagon , Peptídeos Semelhantes ao Glucagon , Humanos , Marcação In Situ das Extremidades Cortadas , Mucosa Intestinal/metabolismo , Intestino Grosso/efeitos dos fármacos , Intestino Grosso/crescimento & desenvolvimento , Intestino Grosso/metabolismo , Intestinos/efeitos dos fármacos , Masculino , Pâncreas/efeitos dos fármacos , Pâncreas/crescimento & desenvolvimento , Pâncreas/metabolismo , Peptídeos/sangue , Estômago/efeitos dos fármacos , Estômago/crescimento & desenvolvimento , Suínos
15.
Am J Physiol Regul Integr Comp Physiol ; 279(6): R2287-96, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11080097

RESUMO

Intestinal development is typically studied using omnivores. For comparative purposes, we examined an altricial carnivore, the mink (Mustela vison). In mink, intestinal dimensions increase up to 8 wk after birth and then remain constant (length) or decrease (mass) into maturity despite continuing gains in body mass. Rates of glucose and fructose transport decline after birth for intact tissues but increase for brush-border membrane vesicles (BBMV). Rates of absorption for five amino acids that are substrates for the acidic (aspartate), basic (lysine), neutral (leucine and methionine), and imino acid (proline) carriers increase between birth and 24 h for intact tissues before declining, but increase after 2 wk for BBMV. The proportion of BBMV amino acid uptake that is Na(+)-dependent increases during development but for aspartate is nearly 100% at all ages. Tracer uptake by BBMV can be inhibited by 100 mmol/l of unlabeled amino acid, except for lysine. BBMV uptake of the dipeptide glycyl-sarcosine does not differ between ages, is not Na(+) dependent, and is only partially inhibited by 100 mmol/l unlabeled dipeptide. Despite the ability to rapidly and efficiently digest high dietary loads of protein, rates of amino acid and peptide absorption are not markedly higher than those of other mammals.


Assuntos
Aminoácidos/metabolismo , Absorção Intestinal , Mucosa Intestinal/fisiologia , Intestino Delgado/fisiologia , Vison/crescimento & desenvolvimento , Monossacarídeos/metabolismo , Envelhecimento , Animais , Ácido Aspártico/metabolismo , Peso Corporal , Feminino , Frutose/metabolismo , Glucose/metabolismo , Mucosa Intestinal/crescimento & desenvolvimento , Intestino Delgado/crescimento & desenvolvimento , Leucina/metabolismo , Lisina/metabolismo , Masculino , Metionina/metabolismo , Microvilosidades/fisiologia , Prolina/metabolismo
16.
Comp Biochem Physiol B Biochem Mol Biol ; 125(3): 317-35, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10818266

RESUMO

Groups of fresh- and seawater-adapted Atlantic salmon (Salmo salar L.) and rainbow trout (Oncorhynchus mykiss) were fed diets with (SBM diet) or without (control diet) extracted soybean meal (30% of protein substituted with SBM) for 3 weeks. Average fish size per group ranged from 597 to 1763 g. One tank or net pen per species, dietary group and water salinity was used. In vitro nutrient transport (D-glucose, the L-amino acids aspartate, lysine, methionine, phenylalanine and proline, and the dipeptide glycyl-sarcosine) was measured using intact tissue (everted sleeve method) from the different postgastric intestinal regions. The dimensions of the different intestinal regions were also measured for each treatment group. Results indicate that SBM causes decreased carrier-mediated transport and increased permeability of distal intestinal epithelium for the nutrients, and the capacity of this region to absorb nutrient was diminished. Salinity may also affect the relative contribution of carrier-mediated and independent uptake to total nutrient absorption.


Assuntos
Absorção Intestinal , Mucosa Intestinal/metabolismo , Oncorhynchus mykiss/metabolismo , Salmo salar/metabolismo , Água do Mar , Proteínas de Soja/administração & dosagem , Aminoácidos/administração & dosagem , Aminoácidos/metabolismo , Animais , Proteínas de Transporte/metabolismo , Proteínas Alimentares/administração & dosagem , Dipeptídeos/administração & dosagem , Dipeptídeos/metabolismo , Glucose/administração & dosagem , Glucose/metabolismo , Técnicas In Vitro , Absorção Intestinal/efeitos dos fármacos , Mucosa Intestinal/anatomia & histologia , Cinética , Oncorhynchus mykiss/anatomia & histologia , Salmo salar/anatomia & histologia
17.
J Nutr ; 129(7 Suppl): 1446S-50S, 1999 07.
Artigo em Inglês | MEDLINE | ID: mdl-10395618

RESUMO

Because diet can influence the structure and functions of the gastrointestinal tract, there are opportunities for using diet as a "management tool" to affect the resident microbiota. Fermentable fibers increase the densities of beneficial bacteria and stimulate growth and functions of the healthy intestine. Recent findings show that after acute diarrhea, the use of an oral electrolyte solution with the fermentable fiber oligofructose accelerates recovery of beneficial bacteria, reduces the relative abundance of detrimental bacteria, stimulates mucosal growth and enhances digestive and immune functions. This review will focus on how the principles of stream ecology can be applied to better understand the distribution of bacteria along the length of the gastrointestinal tract, the effect of diarrhea on the gastrointestinal ecosystem and how fermentable fibers can be used as a "management tool" to promote gastrointestinal health in normal states and during recovery from diarrhea.


Assuntos
Bactérias/efeitos dos fármacos , Sistema Digestório/efeitos dos fármacos , Sistema Digestório/microbiologia , Inulina/fisiologia , Doença Aguda , Animais , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Diarreia/tratamento farmacológico , Dieta , Ecossistema , Fermentação/efeitos dos fármacos , Hidratação , Humanos , Inulina/farmacologia , Inulina/uso terapêutico , Oligossacarídeos/farmacologia , Oligossacarídeos/uso terapêutico
18.
Am J Vet Res ; 60(3): 354-8, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10188819

RESUMO

OBJECTIVE: To determine whether intestinal dimensions and nutrient absorption are influenced by different types of dietary fiber. ANIMALS: 10 adult Beagles of both sexes. PROCEDURE: Dogs were randomly assigned to 2 groups and fed a diet with fermentable fibers (beet pulp and oligofructose) or a nonfermentable fiber (cellulose) for 6 weeks. Effects of the diets on small intestinal dimensions were measured, and transport rates for glucose and proline were determined. Kinetics of glucose and proline uptake were defined in the proximal and middle regions of the small intestine, respectively. RESULTS: Small intestines of dogs fed fermentable fiber had 28% more nominal surface area and 37% more mucosal mass, were 35% heavier, and had 95% higher capacity for carrier-mediated glucose uptake than those of dogs fed a diet with cellulose. Differences were more pronounced in the proximal portion of the intestine. CONCLUSIONS AND CLINICAL RELEVANCE: Diets containing fermentable fibers increase small intestinal dimensions and the capacity for nutrient absorption in dogs. These changes may reduce the risk of enteric infections or aid in treatment of intestinal diseases, particularly those involving reduced nutrient absorption.


Assuntos
Fibras na Dieta/farmacologia , Cães/metabolismo , Fermentação , Glucose/metabolismo , Intestino Delgado/fisiologia , Prolina/metabolismo , Absorção , Animais , Transporte Biológico , Feminino , Cinética , Masculino
19.
J Nutr ; 128(8): 1302-10, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9687548

RESUMO

Structural and functional responses of the intestine to colostrum, milk replacer, oral electrolyte solution and food deprivation were examined during the first 6 h after birth in pigs. Total intestinal weight, surface area and mucosal mass were highest (P < 0.05) in pigs fed colostrum. The other diet groups did not differ, except that food-deprived pigs had lower surface area than the other groups. Feeding colostrum was associated with higher mucosal protein content (P < 0.05). Total intestinal brush border membrane protein content of pigs fed milk replacer, oral electrolyte solution and food-deprived pigs were 61, 44 and 56%, respectively, of those fed colostrum (P < 0.05). Pigs fed colostrum had higher total mucosal maltase activities than those that were food deprived, and total brush border membrane activities were higher than in those fed oral electrolyte solution. Total intestinal brush border membrane aminooligopeptidase activity was higher in pigs fed colostrum than in those given oral electrolyte solution or deprived of food, but total intestinal homogenate activities did not differ among groups. Diet influenced lactase activity only in the mid-region, and sucrase was not responsive to diet. Intestinal glucose transport capacity by intact intestinal tissues did not differ among diet groups. The ability of brush border membrane vesicles to actively accumulate glucose was lost when pigs were fed colostrum and milk replacer, but not when fed oral electrolyte solution or deprived of food. Our findings reveal how diet during the first 6 h after birth influences the structure and functional characteristics of the intestine. The responses vary between brush border membrane proteins and intestinal regions, and appear to differ from those described for older animals.


Assuntos
Animais Recém-Nascidos/crescimento & desenvolvimento , Dieta , Intestinos/crescimento & desenvolvimento , Suínos/crescimento & desenvolvimento , Animais , Peso Corporal , Antígenos CD13/metabolismo , Colostro , Eletrólitos/administração & dosagem , Feminino , Privação de Alimentos , Glucose/metabolismo , Hexoses/metabolismo , Mucosa Intestinal/crescimento & desenvolvimento , Lactase , Masculino , Microvilosidades/enzimologia , Leite , Tamanho do Órgão , Sacarase/metabolismo , beta-Galactosidase/metabolismo
20.
Dig Dis Sci ; 43(1): 138-47, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9508515

RESUMO

Although oral electrolyte solutions (OES) replenish salts and water lost during diarrhea, present formulations do not address disturbances of the normal intestinal microbiota. Therefore, we evaluated the efficacy of an OES with and without fructooligosaccharide (FOS) for treatment of pigs with acute secretory diarrhea induced by cholera toxin. Before, during, and after diarrhea, bacteriologic evaluation was made of contents collected from the mid small intestine, cecum, and distal colon and mucosa scraped from the mid small intestine. Diarrhea caused significant declines in total bacterial counts of contents from all three regions, with less of an impact on bacteria associated with the mucosa. Although total bacterial counts recovered within 24 hr, regardless of treatment, densities of Enterobacteriaceae were higher in pigs treated with OES whereas those receiving FOS had more lactobacilli. Our results show that secretory diarrhea disturbs the normal densities and relative species abundance of the microbiota, with the influences more pronounced for contents relative to the mucosa, and that adding FOS to OES accelerates the recovery of bacteria perceived as beneficial while potentially slowing the recovery of pathogenic forms.


Assuntos
Diarreia/microbiologia , Diarreia/terapia , Eletrólitos/administração & dosagem , Frutose/administração & dosagem , Intestinos/microbiologia , Oligossacarídeos/administração & dosagem , Soluções para Reidratação/administração & dosagem , Animais , Ceco/metabolismo , Toxina da Cólera , Colo/metabolismo , Diarreia/induzido quimicamente , Enterobacteriaceae/isolamento & purificação , Feminino , Concentração de Íons de Hidrogênio , Mucosa Intestinal/microbiologia , Intestino Delgado/metabolismo , Masculino , Oxirredução , Suínos
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