Effects of hydrocortisone on the formation of gap junctions and the abnormal growth of cilia within the rat anterior pituitary gland: Possible role of gap junctions on the regulation of cell development

We investigated the effects of hydrocortisone on the formation of gap junct ions in and the growth of cilia on folliculo-stellate cells. The male rats of experimental groups were given daily intraperitoneal injections of 5 mg/ kg of hydrocortisone from Day 20 to 60. Five rats were killed at ages 10, 2 0, 30 and 40 days after initiation of injections, and the pituitary gland w as removed from each rat. Then, the specimens were prepared for observation by transmission electron microscopy. A delay in the formation of gap junct ions between folliculo-stellate cells was observed in hydrocortisone treate d rats compared with control rats on Day 30, 40 and 50. Another finding in the present study was the increase of ciliated follicles on Day 40 and 50 i n the hydrocortisone treated groups, simultaneous with the delay in gap jun ction formation. The results suggest that hydrocortisone has a suppressive effect on the gap junction formation between folliculo-stellate cells, and loss of intercellular communication by way of gap junctions may lead to alt eration of morphological development of the cell. Anat Rec 262:169-175, 200 1. (C) 2001 Wiley-Liss, Inc.