Endocrinology is a branch of biology and medicine dealing with the endocrine system, its diseases, and its specific secretions known as hormones. It is also concerned with the integration of developmental events proliferation, growth, and differentiation, and the psychological or behavioral activities of metabolism, growth and development, tissue function, sleep, digestion, respiration, excretion, mood, stress, lactation, movement, reproduction, and sensory perception caused by hormones. Specializations include behavioral endocrinology and comparative endocrinology.
Growth hormone (GH) or somatotropin, also known as human growth hormone in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is thus important in human development. GH also stimulates production of IGF-1 and increases the concentration of glucose and free fatty acids. It is a type of mitogen which is specific only to the receptors on certain types of cells. GH is a 191-amino acid, single-chain polypeptide that is synthesized, stored and secreted by somatotropic cells within the lateral wings of the anterior pituitary gland.
Prolactin, also known as lactotropin, is a protein best known for its role in enabling mammals, usually females, to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pituitary gland in response to eating, mating, estrogen treatment, ovulation and nursing. It is secreted heavily in pulses in between these events. Prolactin plays an essential role in metabolism, regulation of the immune system and pancreatic development.
Amenorrhea is the absence of a menstrual period in a woman of reproductive age. Physiological states of amenorrhoea are seen, most commonly, during pregnancy and lactation (breastfeeding). Outside the reproductive years, there is absence of menses during childhood and after menopause.
Hyperprolactinaemia is the presence of abnormally high levels of prolactin in the blood. Normal levels average to about 13 ng/mL in women, and 5 ng/mL in men, with an upper normal limit of serum prolactin levels being 15-25 ng/mL for both. When the fasting levels of prolactin in blood exceed this upper limit, hyperprolactinemia is indicated.
A major organ of the endocrine system, the anterior pituitary is the glandular, anterior lobe that together with the posterior lobe makes up the pituitary gland (hypophysis). The anterior pituitary regulates several physiological processes, including stress, growth, reproduction, and lactation. Proper functioning of the anterior pituitary and of the organs it regulates can often be ascertained via blood tests that measure hormone levels.
Pituitary adenomas are tumors that occur in the pituitary gland. Pituitary adenomas are generally divided into three categories dependent upon their biological functioning: benign adenoma, invasive adenoma, and carcinomas. Most adenomas are benign, approximately 35% are invasive and just 0.1% to 0.2% are carcinomas. Pituitary adenomas represent from 10% to 25% of all intracranial neoplasms and the estimated prevalence rate in the general population is approximately 17%.
A prolactinoma is a benign tumor (adenoma) of the pituitary gland that produces a hormone called prolactin. It is the most common type of functioning pituitary tumor. Symptoms of prolactinoma are due to too much prolactin in the blood (hyperprolactinemia), or those caused by pressure of the tumor on surrounding tissues. Based on size, a prolactinoma can be classified as a microprolactinoma or a macroprolactinoma.
Pediatric endocrinology is a medical subspecialty dealing with disorders of the endocrine glands, such as variations of physical growth and sexual development in childhood, diabetes and many more.
Multiple endocrine neoplasia type 1 (MEN-1) is one of a group of disorders, the multiple endocrine neoplasias, that affect the endocrine system through development of neoplastic lesions in pituitary, parathyroid gland and pancreas. It was first described by Paul Wermer in 1954.
A craniopharyngioma is a rare type of brain tumor derived from pituitary gland embryonic tissue that occurs most commonly in children, but also affects adults. It may present at any age, even in the prenatal and neonatal periods, but peak incidence rates are childhood-onset at 5–14 years and adult-onset at 50–74 years. People may present with bitemporal inferior quadrantanopia leading to bitemporal hemianopsia, as the tumor may compress the optic chiasm. It has a point prevalence around two per 1,000,000. Craniopharyngiomas are distinct from Rathke's cleft tumours and intrasellar arachnoid cysts.
The prolactin receptor (PRLR) is a type I cytokine receptor encoded in humans by the PRLR gene on chromosome 5p13-14. It is the receptor for prolactin (PRL). The PRLR can also bind to and be activated by growth hormone (GH) and human placental lactogen (hPL). The PRLR is expressed in the mammary glands, pituitary gland, and other tissues. It plays an important role in lobuloalveolar development of the mammary glands during pregnancy and in lactation.
The Endocrine Society is a professional, international medical organization in the field of endocrinology and metabolism, founded in 1916 as The Association for the Study of Internal Secretions. The official name of the organization was changed to the Endocrine Society on January 1, 1952. It is a leading organization in the field and publishes four leading journals. It has more than 18,000 members from over 120 countries in medicine, molecular and cellular biology, biochemistry, physiology, genetics, immunology, education, industry, and allied health. The Society's mission is: "to advance excellence in endocrinology and promote its essential and integrative role in scientific discovery, medical practice, and human health."
Hyperpituitarism is a condition due to the primary hypersecretion of pituitary hormones; it typically results from a pituitary adenoma. In children with hyperpituitarism, disruption of growth regulation is rare, either because of hormone hypersecretion or because of manifestations caused by local compression of the adenoma.
The University of Virginia School of Medicine is the graduate medical school of the University of Virginia. The school's facilities are on the University of Virginia grounds adjacent to Academical Village in Charlottesville, Virginia. Founded in 1819 by Thomas Jefferson, UVA SoM is the tenth oldest medical school in the United States, and is ranked 31st in research-oriented medical schools by U.S. News and World Report, and as of 2021, is ranked nineteenth in the nation in primary care. The School of Medicine confers Doctor of Medicine (M.D.) and Doctor of Philosophy (PhD) degrees, and is closely associated with both the University of Virginia Health System and Inova Health System.
George P. Chrousos is professor of Pediatrics and Endocrinology Emeritus and former chairman of the Department of Pediatrics at the Athens University Medical School, Greece. Earlier he was senior investigator, director of the Pediatric Endocrinology Section and Training Program, and chief of the Pediatric and Reproductive Endocrinology Branch of the National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH). He is also clinical professor of Pediatrics, Physiology and Biophysics at Georgetown University Medical School and distinguished visiting scientist, NICHD, NIH. Dr. Chrousos was the first general director of the Foundation of Biomedical Research of the Academy of Athens (2001–2002). He holds the UNESCO Chair on Adolescent Health Care, while he held the 2011 John Kluge Chair in Technology and Society, Library of Congress, Washington, D.C.
Acromegaly is a disorder that results from excess growth hormone (GH) after the growth plates have closed. The initial symptom is typically enlargement of the hands and feet. There may also be an enlargement of the forehead, jaw, and nose. Other symptoms may include joint pain, thicker skin, deepening of the voice, headaches, and problems with vision. Complications of the disease may include type 2 diabetes, sleep apnea, and high blood pressure.
Dr. Hossein Gharib is a physician who specializes in thyroid disorders. He was born in Tehran, Iran, on February 2, 1940, and is a consulting physician at the Mayo Clinic in Rochester, Minnesota.
Mitchell Lazar is an endocrinologist and physician-scientist known for his discovery of the hormone resistin and his contributions to the transcriptional regulation of metabolism.
Grant Winder Liddle was an American endocrinologist whose research focused largely on the hypothalamic–pituitary–adrenal axis. He was a professor at Vanderbilt University and chaired its Department of Medicine from 1968 to 1983.
