Morphological and quantitative study of the myenteric plexus of the duodenum of streptozotocin-induced diabetic rats.

The purpose of this work was to study the morphological and quantitative alterations of the myenteric plexus neurons of the duodenum of rats with acute and chronic streptozotocin-induced diabetes and establish a comparison with non-diabetic animals. Samples of duodenum were destined to histological sections stained by Hematoxilin-Eosin and to membrane preparings stained by the Giemsa and NADH-diaphorasis methods. Small, medium and large neurons were found, with a predominance of medium ones on chronic and acute diabetic animals. It was verified that most of the neurons of diabetic and non-diabetic animals have an eccentrical nucleus and thus this characteristic is not an indicative of degenerative process. It was observed that in diabetes there is a decrease in the number of myenteric neurons. It is argued that this initial decrease is due to the toxic effects of the drug and not to the physiopathology of diabetes itself, and also that the expressive smaller proportion of neurons on the chronically diabetic animals is due to the immediate loss related to streptozotocin and the further consequences of aging during nine weeks of diabetes.