Morphological Characteristics of Changes in the Duodenal Wall Within 14-56 Days of the Development of Streptozotocin-Induced Experimental Diabetes Mellitus

Abstract

The objective of the research was to determine the morphological features of the duodenal wall of animals within 14-56 days of developing streptozotocin-induced diabetes mellitus using light optical microscopy.

Materials and Methods. The research was carried out on 40 white nonlinear adult male rats. Diabetes mellitus was simulated by a single intraperitoneal injection of streptozotocin (Sigma, USA) at a dose of 60 mg/kg body weight. The material was taken from the duodenum on the 14^th, 28^th and the 56^th days after the onset of experimental diabetes mellitus. For histological study, the preparations were made using the conventional method, which included the staining of sections with hematoxylin and eosin.

Results. Streptozotocin-induced diabetes mellitus was experimentally found to lead to dystrophic changes in the epithelial components of the duodenal mucosa from the 14^th day of developing. There were observed a shortening of the villi of the mucous membrane and a lack of distinctness of striated border contours on the apical surface of epitheliocytes. Between the connective-tissue fibers of the lamina propria of the mucosa and thin-walled vessels, the cellular elements, including mainly macrophages, lymphocytes, were found. There was a shortening of the villi, edema and histiolymphocytic infiltration of the villous stroma 28 days after developing experimental diabetes mellitus. The epithelium covering was discontinuous; numerous areas of desquamation were found at the apex of the villi. Fifty-six days after developing experimental diabetes mellitus, the destruction and desquamation of the epithelium of the villi and crypts were observed. The surface of the duodenal mucosa smoothed down due to the shortening and flattening of the villi (indicating their atrophy), while the crypts elongated and their depth increased.

Conclusions. Histological study of the duodenal wall of diabetic animals showed pronounced desquamation at the apex of the villi, destructive and dystrophic changes in the surface epithelium, edema and increased cellular infiltration of the lamina propria of the mucosa. Thus, in diabetes mellitus, structural changes in the duodenal wall of rats are characterized by the dystrophic processes, which can be considered as the morphological reflection of enteropathy.