In vitro studies on the effects of ranitidine on isolated anterior pituitary and adrenal cells

The effects of ranitidine on anterior pituitary and adrenal function have been studied using isolated perfused rat anterior pituitary and zona glomerulosa cells. Ranitidine did not have pituitary hormone releasing activity with respect to LH, TSH, GH and ACTH. It also did not alter prolactin secretion in experiments designed to test whether it acted as a dopamine agonist or antagonist. In the adrenal cell studies ranitidine infusion stimulated basal aldosterone secretion and inhibited the release of aldosterone in response to angiotensin II, but not to ACTH. These experiments suggest that ranitidine is unlikely to alter pituitary hormone secretion by a direct action on the pituitary. The drug, however, can affect aldosterone secretion in vitro and further in vivo studies are required to elucidate the significance of this.