Influence of D-galactosamine and alpha-naphthylisothiocyanate on the activities of some intestinal enzymes.

The activities of lactase, sucrase, maltase and gamma-glutamyl transferase (gamma-GT) were determined in homogenates of rat jejunal mucosa 24 h after acute administrations of D-galactosamine (GALN) (1.855 mmol/kg; i.p. injection) and alpha-naphthyl-isocyanate (ANIT) (0.540 mmol/kg; given by gastric tube). The animals were fasted either 24 h or 72 h prior to sacrifice. In rats fasted only 24 h, GALN treatment resulted in a pronounced decrease in lactase and in a moderate elevation of sucrase and maltase. ANIT clearly reduced lactase and, to a lesser extent, sucrase, while it increased maltase. Seventy-two hour fasting has a modifying role. All disaccharidase activities tended to decrease, except for maltase in the ANIT treated group, where an increase was recorded. gamma-GT showed no significant changes after either GALN or ANIT treatment in rats fasted 24 h. However, the 72-hour food deprivation diminished it in ANIT intoxication. It is obvious that the intestinal enzymes are influenced by the hepatic damage produced by GALN and ANIT.