Effects of ketoacids on liver glutathione and microsomal enzymes in malnourished rats.

The progression of chronic renal failure is delayed by the use of low protein diets, but such diets are deficient in essential amino acids. In order to maintain good nutritional status, branched-chain ketoacids (BCKA) can be added to these diets. The effects of BCKA on protein metabolism in skeletal muscle is well established, but there is little information about their effects on liver metabolism. Protein deprivation affects some aspects of liver function such as drug metabolism (glutathione, cytochrome P-450 and enzymes). In a chronic protein malnutrition model, we have tested the efficacy of BCKA to correct these abnormalities when they are added to a low protein diet. RNA/DNA, liver proteins, microsomal proteins and glutathione were markedly improved; cytochrome P-450 was only partly improved, and aminopyrine demethylase was not affected. In conclusion, this study suggests that BCKA have a beneficial effect and may prevent the deterioration in the nutritional state of the liver in uremic patients.

Rehabilitation of microsomal enzymes in malnourished rats: comparison of parenteral versus oral refeeding.

Protein malnutrition decreases the activity of drug-metabolizing liver microsomal enzymes. In the first part of our study, we evaluated those enzymes during malnutrition and refeeding. Then we compared the effects of different nutritional patterns on these parameters. During malnutrition (M), rats were fed a 5% casein diet. During refeeding, they were randomized in 3 groups: oral refeeding (20% casein diet: A), continuous total parenteral nutrition (TPN: B) and oral energy refeeding (glucose + lipids) + continuous amino-acid infusion (C). Rats were sacrificed before and at various times during malnutrition and refeeding (2 to 28 days). There was no difference in caloric intake between the 3 groups. Nitrogen balance was not different in A and B. It was lower in C, though nitrogen intake was not different. Body and liver weights were not different between the 3 groups. Microsomal proteins and cytochrome P-450 were improved in A and B but not in C compared to M. Our results suggest that TPN (but not continuous amino-acids infusion + oral energy intake) is as effective as oral nutrition on rehabilitation of microsomal enzymes in malnourished rats.

[Transfer of the cecal flora of the hamster to the germfree C3H mouse: use of this model to study the flora of the anti-Clostridium difficile barrier]. / Transfert de la flore caecale du hamster à la souris C3H axénique: utilisation de ce modèle pour étudier la flore de barrière anti-Clostridium difficile.

The purpose of this work was the research and development of an experimental model to study anti-Clostridium difficile caecal microflora in the hamster. First the existence of this "barrier" was verified in conventional hamsters. Then, the caecal flora from these animals was orally transferred to C3H germfree mice. The barrier effect was maintained in the axenic mice. The comparative bacteriological analysis of hamster and mouse feces did not reveal important variations in the dominant anaerobic flora (P less than 0.01). After treatment with erythromycin, the barrier effect was maintained and while the disappearance of Escherichia coli was observed, the dominant anaerobic flora persisted. After dilution (10(-2] and subsequent heating (70 degrees C, 10 min) of caecal contents, the inhibitory activity against C. difficile was maintained although the number of aerobic and aerotolerant bacteria was reduced. The isolation from caecal microflora of anaerobic strains implicated in the resistance to colonization is presently underway in Freter anaerobic chambers.

[Evaluation of an experimental animal model allowing the study of the cecal microflora in the hamster, antagonistic to clostridium difficile]. / Mise au point d'un modèle expérimental animal permettant l'etude de la microflore coecale du hamster, antagoniste de Clostridium difficile.

The purpose of this study was the development and evaluation of an experimental model allowing the investigation of hamster anti-Clostridium difficile coecal microflora. The existence of this "barrier" was verified in conventional hamsters. Such hamster coecal flora was then orally transferred to C3H germ-free mice. In such animals, the "barrier effect" was maintained. After treatment with erythromycin, the colonization resistance was always maintained; despite two subsequent processes, dilutions of coecal contents (10(-2] and subsequent heating of this fluid (70 degrees C, 10 min), the inhibitory activity against C. difficile was partially maintained (10(4) UFC/g faeces). The isolation of anaerobic strains implicated in colonization resistance will next be carried out in an anaerobic chamber using this microflora.

[Effect of yogurt ingestion on the intestinal lactase activity in axenic or holoxenic mice]. / Influence de l'ingestion de yogourt sur l'activité lactasique intestinale chez des souris axéniques ou holoxéniques.

Two sets of mice just weaned (germ-free or conventional) were fed ad libitum with three different diets: a 5% lactose solution, yogurt at a 3/5 dilution in this lactose solution, and heated yogurt at the same dilution in the same solution. Total lactase activity (TA) and specific lactase activity (SA) of the small intestine were measured after 14, 28 and 42 days of these diets. The results led to the following conclusions. 1) TA and SA were always significantly greater in germ-free and gnotobiotic animals than in conventional ones, whatever the diets and age of the animals. 2) TA and SA were significantly greater at the three times of measurement in the gnotobiotic and conventional animals fed with unheated yogurt than in the animals fed with heated yogurt. The 5% lactose solution gave intermediate results. 3) In conventional and gnotobiotic animals fed with yogurt, TA increased with time compared to the initial value at weaning. With the two other diets, TA remained constant or decreased. With yogurt, SA varied only weakly with time compared to weaning values, when it decreased in greater proportions with the two other diets.