Induction of intestinal mucosal atrophy by difluoromethylornithine: a nonuremic model of enhanced aluminum absorption.

The intestinal absorption of aluminum (Al) appears to be enhanced in the uremic rat. Since atrophic changes of the intestinal mucosa have been observed in uremia the present study investigated whether intestinal atrophy induced by difluoromethylornithine (DFMO), a specific inhibitor of ornithine decarboxylase, could affect the absorption of Al. DFMO supplied with the drinking water (5%) to rats with normal renal function for 9 days resulted in a reduced number of microvilli with definite morphological alterations in small intestinal mucosa. Following an oral load of Al urinary excretion rates and 1-hour postload serum concentrations of Al were increased in DFMO-treated rats as compared to controls suggesting enhanced absorption of Al. Pattern and degree of urinary Al excretion as well as ultrastructural alterations of the intestinal mucosa were similar in DFMO-treated rats and uremic rats. The model of DFMO-induced intestinal alterations suggests that structural lesions of the intestine may be involved in the enhanced absorption of Al in uremia.