EFFECT OF MATERNAL ADRENALECTOMY AND CORTICOSTERONE THERAPY ON THE EARLY DEVELOPMENT OF B-CELLS IN THE FETAL PANCREATIC-ISLET IN THE RAT

Pregnant Wistar rats were divided into 3 groups, non-operated control, adrenalectomized, and adrenalectomized and corticosterone-treated. Ma ternal adrenalectomy was performed on day 6 of gestation. Corticostero ne therapy was made from the day at operation to the day at observatio n. The growth pattern of insulin-producing B-cells was observed immuno histochemically and histometrically from days 12 to 16. The results ob tained were as Follows: From day 12 to day 15, maternal adrenalectomy resulted in a significant retardation of the growth of insulin-positiv e B-cells in terms of the collective volume of the cells. Maternal cor ticosterone therapy prevented this retardation. On day 16, however, th e growth of B-cells in collective volume overcame the suppressive effe ct of maternal adrenalectomy. These results suggest that the lack of a drenocortical hormones causes a retardation of B-cell growth in early development, and that, when once developed well, B-cells can grow inde pendently of the hormones.