Intestinal mucosal changes following induced hypothyroidism in the developing rat.

In this study, morphological changes which occur in the small intestine of hypothyroid rats are described. Hypothyroidism was induced during the first 24 h postnataly. - Samples from duodenojejunal and ileocecal junctions were taken, and histologic, histomorphometric, and ultrastructural studies were performed. The most prominent feature was the decrease of the villous height and total mucosal thickness. At electron microscopic level, microvillous height was also markedly decreased. These changes probably represent a direct effect of hormonal deprivation upon the intestinal mucosa, combined with the effect that hypothyroidism may have on the villi.