Biomedical subjects

F Raul

Publications and source records attributed to F Raul.

114 records · Page 7Linked to original sources

PubMedDate not supplied

Prenatal exposure to alcohol in rat: effect on intestinal enzymes in offspring.

Intestinal hydrolase activities were studied during postnatal development in the offspring of rats exposed to 20% ethanol during gestation; alcohol was withdrawn at birth. Controls received water during gestation. Sucrase, lactase, glucoamylase and aminopeptidase activities were determined 2 and 4 weeks after birth in the proximal jejunum. Offspring prenatally exposed to ethanol showed a deficit in body weight and lower aminopeptidase activity during the suckling period (2 weeks). These effects were reversible by 4 weeks when alcohol was withdrawn at birth. The prenatal exposure to ethanol did not change the pattern of sucrase maturation in the intestine of offsprings. The activities of lactase and glucoamylase were not modified following prenatal exposure to ethanol. In conclusion, exposure to ethanol during gestation caused decreased abilities for the intestine of the offspring to digest protein.

Animals↗

PubMedDate not supplied

A comparison of intestinal adaptation to short-term intravenous versus intragastric diet in adult rats.

This study was designed to determine, on intestinal function, the comparative effects of a fat emulsion, a carbohydrate solution, and a mixture of lipids and carbohydrates given for 4 days to adult rats either intragastrically or intravenously. The rats were separated into three groups (n = 24 in each group). Each group was divided into two populations fed either intragastrically or intravenously. Each group received one of the following nutrients: a 20% Intralipid emulsion, a mixture (1:1, V/V) of Intralipid 20% and Vamine N containing 25% glucose (W/V), a solution of Vamine-glucose supplemented with fructose to reach a final concentration of 20% (W/V). Sham-operated rats that received laboratory chow orally were used as controls. The daily caloric intake was 0.21 to 0.22 kcal/g body weight. The studies on villus morphology and on brush border enzyme activities were performed on the proximal part of the jejunum. For all nutrients, intragastric infusion provoked an increase in the villus height. The lipids were the only nutrients to cause villus lengthening by the intravenous route. Intragastric or intravenous infusion of fat provoked a deficiency in intestinal disaccharidases; the presence of carbohydrates in the diet inhibited this effect slightly. Carbohydrates given alone, either intragastrically or intravenously, caused an elevation of lactase activity. Independent of diet composition, aminopeptidase activity was reduced after intravenous feeding. In conclusion, the disaccharidase activities are largely dependent on changes occurring in the nutrient composition given either intragastrically or intravenously, whereas amino-peptidase activity was related to the route of diet administration.

Aminopeptidases↗

PubMedDate not supplied

Imbalance between jejunum and ileum in the response of brush border hydrolases to oral feeding after intravenous alimentation in rats.

The effect of oral refeeding after total parenteral nutrition (TPN) on brush border hydrolases was measured in the proximal jejunum and ileum of adult rats. The animals received intravenously for 4 days a mixture of Intralipid 10% and Vamine-Glucose. At the end of TPN, oral feeding was reinstituted and the rats were fed with an isocaloric standard diet (60% carbohydrate, 17% protein, 3% lipid). Sucrase, isomaltase, lactase, and aminopeptidase N activities were measured at the end of TPN and at 1, 3, and 5 days after TPN. Sham-operated rats nourished orally with the standard diet were used as controls. In both intestinal segments, lactase activity showed no significant changes at the end of TPN or during oral realimentation. Isomaltase, and especially sucrase activities, exhibited an important drop at the end of TPN. After TPN, a complete restoration of isomaltase and sucrase activities was obtained in the jejunum only. During oral refeeding a 40% deficit in sucrase activity persisted in the ileum throughout the experimental period, whereas normal isomaltase activity was restored in this segment. Aminopeptidase N activity was lowered by TPN and recovered normal values within a few hours after oral realimentation. Thus, reinstitution of oral feeding after TPN should take into account that the intestine is capable of digesting normal amounts of dietary protein but has a reduced tolerance for carbohydrates.

Animals↗

PubMedDate not supplied

Effects of amino acids in mixtures given by enteral or parenteral route on intestinal morphology and hydrolases in rats.

This study compares the effects of amino acid addition to an elemental liquid diet containing carbohydrates and triglycerides given either intragastrically or intravenously on the morphology and on hydrolase activities in the jejunum and ileum of adult rats. The isocaloric mixtures were administered for 4 days and control rats received an isocaloric laboratory diet orally. Independent of their content in amino acid, all mixtures given intravenously caused a drop in mucosal weight and a shortening of the height of the villi in both the jejunum and ileum. By enteral route, the addition of amino acids to a carbohydrate-triglyceride liquid diet led to the maintenance of normal villus height (this effect being prominent in the ileum) and to a significant increase of jejunal sucrase and aminopeptidase activities when compared with the carbohydrate-triglyceride mixture. Feeding the mixtures by parenteral route caused a significant drop of both enzyme activities. In contrast, lactase activity was generally not modified by the route of nutrient administration or by the composition of the diets. However, the absence of amino acid in the mixture given intravenously caused a specific drop of lactase activity in the ileum. Ileal sucrase activity was lowered dramatically by intragastric or intravenous feeding of the elemental diets. This effect was not modulated by the presence of amino acids. The presence of amino acids caused a significant drop of aminopeptidase activity in the ileum independently of the route of administration when compared with animals receiving the carbohydrate-triglyceride liquid diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗

PubMedDate not supplied

Functional and metabolic changes in intestinal mucosa of rats after enteral administration of ornithine alpha-ketoglutarate salt.

BACKGROUND: Ornithine alpha-ketoglutarate salt efficiently improves the nutritional status of protein-depleted patients. Our aim was to explore the effects of ornithine alpha-ketoglutarate supplementation on intestinal physiology in healthy animals. METHODS: Rats were given a nutritive mixture supplemented with ornithine alpha-ketoglutarate (1 g.kg-1 per day) by enteral route for 7 days. Controls received the diet supplemented with casein acid hydrolysate under isoenergetic and isonitrogenous conditions. RESULTS: An adaptive hyperplasia of the villi and an increase in the brush-border hydrolase activities were observed in rats receiving ornithine alpha-ketoglutarate. Because of the high ornithine aminotransferase activity, ornithine alpha-ketoglutarate-derived ornithine was extensively transaminated with a concomitant enhancement of ornithine decarboxylation. Surprisingly, with glutamate and putrescine, the products of ornithine transamination and decarboxylation, gamma-aminobutyric acid accumulated (10-fold to 16-fold) dramatically in the intestinal mucosa of rats treated with ornithine alpha-ketoglutarate. Because gamma-aminobutyric acid formation was completely prevented by the diamine oxidase inhibitor aminoguanidine but was not modified after inactivation of ornithine aminotransferase by 5-fluoromethylornithine, it is evident that gamma-aminobutyric acid is formed in the mucosa from ornithine via putrescine as an intermediate. CONCLUSIONS: It is assumed that enhanced gamma-aminobutyric acid formation in the intestinal mucosa by ornithine alpha-ketoglutarate treatment might be of physiologic importance in the regulatory processes of cell growth and differentiation.

Amino Acids↗

PubMedDate not supplied

[Modulatory effects of polyamines and GABA on rat ileal motility in vitro].

AIM: The aim of our work was to determine the effects of polyamines and GABA on rat ileum motility in vitro. METHODS: Longitudinal strips dissected from control ileum or ileum without myenteric plexus after benzalkonium chloride (BAC) treatment were placed in organ bath chambers. RESULTS: Spermine significantly inhibited spontaneous activity and nerve stimulation-induced response. Inhibition of spontaneous activity was not altered by BAC treatment or tetrodotoxin but was antagonized by BAY K 8644, a L-type calcium channel agonist. Spermine inhibitory effect on nerve-stimulation induced response disappeared after BAC treatment. GABA enhanced the response induced by nerve stimulation but did not antagonize spermine effects; its action was inhibited in presence of atropine and was mimicked by baclofen, a GABAB agonist. CONCLUSION: Polyamines and GABA can modulate rat ileum motility in vitro. GABA acted via neural GABAB receptors. We demonstrate for the first time that spermine exerts a dual action through different mechanisms on both smooth muscle cells and probably intramural neurons.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗