The adenohypophysis, or anterior pituitary, is the anterior lobe of a person’s pituitary gland. A person’s pituitary gland is generally located below the brain and is controlled by a portion of this organ known as the hypothalamus. The anterior pituitary secretes several different hormones that have important functions throughout the body. Some of the hormones that are released by the adenohypophysis include thyroid-stimulating hormone, growth hormone and adrenocorticotropic hormone. Several medical conditions may affect the anterior pituitary, such as hypopituitarism and Sheehan’s syndrome.
Thyroid-stimulating hormone from the anterior pituitary gland typically prompts the thyroid gland to secrete several types of thyroid hormones. The adenohypophysis also releases growth hormone that targets the liver and helps regulate the metabolism of lipids, carbohydrates and proteins. Adrenocorticotropic hormone from the anterior pituitary influences the adrenal glands and usually causes the adrenals to secrete glucocorticoid hormones. A person’s anterior pituitary gland also may release prolactin that stimulates the mammary glands to produce milk. Follicle-stimulating hormone and luteinizing hormone are two types of adenohypophysis hormones that can affect the reproductive system.
Hypopituitarism is a medical disorder that exists when an individual has an underactive pituitary gland. This condition causes an insufficient release of one or more of the pituitary hormones, including hormones from the adenohypophysis. People may develop hypopituitarism from several different causes, including brain tumors, brain infections and head trauma. Doctors typically use blood tests of pituitary hormones to help them diagnose individuals with hypopituitarism. A magnetic resonance imaging (MRI) test of the pituitary gland or a computerized tomography (CT) scan of the brain may provide detailed images of tumors or other abnormalities.
Symptoms of hypopituitarism can be varied and depend on the number and type of deficient pituitary hormones as well as their effect on other organs in the body. Some people with this disease may develop abdominal pain, infertility and lack of sexual interest. Fatigue, visual problems and stunted growth can occur with hypopituitarism. Doctors generally treat an underactive pituitary gland with replacement of deficient pituitary hormones and other deficient hormones. Infertility from hypopituitarism may be treated with drug therapy in some cases.
Sheehan’s syndrome is a form of hypopituitarism that can strike mothers who experience severe bleeding during childbirth. Excessive bleeding may cause tissue death in portions of the pituitary gland and restrict the ability of the gland to function correctly. Fatigue, low blood pressure and an inability to breast-feed have been reported by some women with this condition. Physicians typically treat this disorder with estrogen- and progesterone-replacement therapy as well as replacement of thyroid and adrenal hormones.