RESUMEN
The effect of vincristine treatment on the morphofunctional status of the small intestine was studied morphologically in 80 Wistar rats. The drug was found to possess a general toxic effect. Diarrhea was matched by the arrest of crypt cell-proliferation at metaphase, lysis, a decreased disaccharidase activity and increased levels of cytoplasmic alkaline phosphatase and dipeptidyl(amino)peptidase-IV in enterocytes of the villi. Exudation and degenerated cell organellae prevailed in intramural nervous ganglion cells, smooth muscle cells of intestinal tunica muscularis and vessels and in endothelium. The said changes were transitory in epithelium, but never regressed in nervous structures. At later stages (6-12 months after vincristine, but never regressed in endothelium. The later stages (6-12 months after vincristine treatment), secondary dystrophic changes developed in the small intestine wall, being predominantly confined to neuromuscular and vascular elements.