Pineal´s influence upon the adrenal cortex

Abstract

Several glands interfere in the production and secretion of adrenocortical hormones. It has been demonstrated, by several studies, the inhibitory effect of pineal on these hormones. Therefore, the pinealectomy increases adrenocortical levels of hormones and promotes morphologic changes in the adrenal, such as decrement of mitotic activity and cortical hypertrophy. The aim of this present study was to verify the influence of the pinealectomy of rats adrenal glands. Four animals groups were selected, a control group, one submitted to sham surgery and two pinealectomized groups, sacrificed in different periods of time. Morphometric and cellular proliferation analysis of the adrenal cortical layers were performed. The morphometric study demonstrated an increase in the fasciculate layer from pinealectomized animals, as compared to control and sham surgery rats. The results showed that pineal exerts influence upon the adrenals and the absence of the pineal promotes weight increase of the adrenal by cellular hypertrophy, but not hyperplasia of the fasciculate layer.