RESUMEN
Rats were maintained 4 weeks on a zinc deficient diet from the time of weaning. A control group received the same basic diet supplemented with zinc. Zinc deficiency, was indicated by poor weight gain, diarrhea, exudative vesicular dermatitis around ears, eyes, nose and extremities, and lowering of blood zinc levels. The morphometric study of the small intestine showed: 1) decreased thickness of the intestinal wall and of the mucosa; 2) significant decrease of the mean villies length and of the mean crypt depth; 3) no alterations in the height of the enterocytes from the middle one third of the villis and in the number of Paneth cells; 4) a decreased mitotic index; 5) a diminished number of epithelial cells living the ville, and 6) a decreased population of intraepithelial lymphocytes, both in the proximal jejunum and distal ileum. These findings are compatible with an impairment of cell replication in the small intestine in experimental zinc deficiency in rats, and allow us to speculate that the diarrhea usually seen in states of zinc malnutrition, at least in part, could be dependent on these changes.