Effect of lactose induced diarrhea on intestinal glutaminase and muscle glutamine synthetase activities in rats.

This study was performed to evaluate the effect of lactose induced diarrhea on the key enzymes of glutamine metabolism in skeletal muscle and small intestine, in rats. As compared to weight paired controls, animals with diarrhea presented higher muscle glutamine synthetase activity associated with reduced skeletal muscle glutamine concentration with a fall in arterial glutamine and an increased intestinal glutaminase activity. These alterations are similar to those reported by others in conditions in which accelerated muscle proteolysis is likely to occur such as in sepsis and after surgery. Besides the data suggestive of an overall alterations in glutamine metabolism, an important finding of this study was the increase in specific activity of intestinal phosphate dependent glutaminase in rats with diarrhea. This enzyme has been shown not to respond to many conditions such as acidosis, alkalosis or increased glutamine ingestion through drinking water or diet.