Anterior pituitary cascading physiological responses. Hormone secretion from the anterior pituitary gland is regulated by hormones secreted by the hypothalamus. Neuroendocrine cells in the hypothalamus project axons to the median eminence, at the base of the brain. At this site, these cells can release substances into small blood vessels that travel directly to the anterior pituitary gland (the hypothalamo-hypophyseal portal vessels). Aside from hypothalamic control of the anterior pituitary, other systems in the body have been shown to regulate the anterior pituitary’s function. GABA can either stimulate or inhibit the secretion of luteinizing hormone (LH) and growth hormone (GH) and can stimulate
Pituitary apoplexy who could be treated conservatively. After an episode of pituitary apoplexy, 80% of people develop hypopituitarism and require some form of hormone replacement therapy. The most common problem is growth hormone deficiency, which is often left untreated but may cause decreased muscle mass and strength, obesity and fatigue. 60–80% require hydrocortisone replacement (either permanently or when unwell), 50–60% need thyroid hormone replacement, and 60–80% of men require testosterone supplements. Finally, 10–25% develop diabetes insipidus, the inability to retain fluid in the kidneys due to a lack of the pituitary antidiuretic hormone. This may be treated with the drug desmopressin, which