PRL and pituitary gland adenoma: NO activates release of luteinizing hormone-releasing hormone (LHRH) and follicle-stimulating hormone-releasing hormone (FSHRH) from the hypothalamus, and of LH and FSH from the pituitary [46-48], stimulates or inhibits the secretion of PRL [49], regulates growth hormone (GH) secretion in the normal human pituitary and in acromegaly [50,51], and modulates GH secretion in a dose-dependent manner in GH adenomatous cells from human pituitary adenomas [52].