Comparative Study of Histological and Kinetic Variations of the Digestive Mucosa and Pancreatic Parenchyma after Hypophysectomy in the Rat

Abstract
Variations of the pancreatic parenchyma, the gastric mucosa and the intestinal mucosa were studied in adult male Wistar rats on day 8 and 15 after hypophysectomy. All results were compared with those obtained in pair-fed control rats. Hypophysectomy affected small intestine as well as gastric mucosa. Hypotrophy was observed on day 8 as most of the morphological parameters reached the maximal decrease. By contrast, hypoplasy occurred on day 15, when the labeling index (LI) decreased significantly. In the intestine, however, a decrease of the LI was observed only for the upper proliferative cells of the crypts. In the gastric mucosa, the LI was reduced only in the proliferative zone containing progenitor cells (isthmic region). Consequently, the cell differenciation is not similarly affected on all levels of the digestive tract.