Effects of postweaning protein malnutrition on intestinal inositol phosphatase activities in normally weaned and neonatally undernourished rats.

Postweaning protein malnutrition imposed on normally weaned or neonatally undernourished rats fed a low-protein diet induced retardation of body and small intestinal growth. A sparing effect on intestinal growth as compared to body growth was observed during protein malnutrition. Postweaning protein malnutrition in normally weaned rats resulted in a significant elevation of specific activities of inositol triphosphatase and phytase in duodenum and jejunum without affecting the activity in ileum. On the other hand, protein malnutrition imposed on neonatally undernourished rats resulted in a significant decrease of enzyme activities in small intestinal segments. These results suggest altered activity of intestinal inositol phosphatase in postweaning protein malnutrition with the direction of effects dependent on the neonatal nutritional status.