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Hypothalamic–pituitary–prolactin Axis
The hypothalamic–pituitary–prolactin axis (HPP axis), also known as the hypothalamic–pituitary–mammary axis or hypothalamic–pituitary–breast axis, is a hypothalamic–pituitary axis which includes the secretion of prolactin (PRL; luteotropin) from the lactotrophs of the pituitary gland into the circulation and the subsequent action of prolactin on tissues such as, particularly, the mammary glands or breasts. It is involved in lobuloalveolar maturation of the mammary glands during pregnancy and the induction and maintenance of lactation following parturition. Hormones that control the secretion of prolactin from the pituitary gland include dopamine ("prolactin-inhibiting factor", or "PIF"), estradiol, progesterone, thyrotropin-releasing hormone (TRH), and vasoactive intestinal peptide (VIP). See also * Prolactin modulator * Hyperprolactinemia * Hypoprolactinemia Hypoprolactinemia is a medical condition characterized by a deficiency in the serum levels of the hyp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PRL Structure
PRL may refer to: Places * Polish People's Republic (''Polska Rzeczpospolita Ludowa''), 1952–1989 * Punggol Regional Library, an upcoming regional library in Punggol, Singapore Business and enterprises * Penn Eastern Rail Lines, reporting mark Computing and technology * Preferred Roaming List, in CDMA phones * Proportional reduction in loss, a measure of reliability * Protocol-relative link, URLs which do not specify a protocol Organizations * Liberal Reformist Party (Dominican Republic) * ''Parti Réformateur Libéral'', a former political party in Belgium * Party of the Radical Left (''Partija radikalne levice''), a political party in Serbia * Republican Party of Liberty, a conservative political party in France, 1945–1951 Science and healthcare * Physical Research Laboratory, India * ''Physical Review Letters'', a scientific journal * PRL-8-53, Nootropic research chemical * Prolactin Prolactin (PRL), also known as lactotropin, is a protein best known for its role i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parturition
Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the fetus at a developmental stage when it is ready to feed and breathe. In some species the offspring is precocial and can move around almost immediately after birth but in others it is altricial and completely dependent on parenting. In marsupials, the fetus is born at a very immature stage after a short gestation and develops further in its mother's womb pouch. It is not only mammals that give birth. Some reptiles, amphibians, fish and invertebrates carry their developing young inside them. Some of these are ovoviviparous, with the eggs being hatched inside the mother's body, and others are viviparous, with the embryo developing inside her body, as in the case of mammals. Mammals Large mammals, such as primates, cattle, horses, some ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breastfeeding
Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that breastfeeding begin within the first hour of a baby's life and continue as often and as much as the baby wants. Health organizations, including the WHO, recommend breastfeeding exclusively for six months. This means that no other foods or drinks, other than vitamin D, are typically given. WHO recommends exclusive breastfeeding for the first 6 months of life, followed by continued breastfeeding with appropriate complementary foods for up to 2 years and beyond. Of the 135 million babies born every year, only 42% are breastfed within the first hour of life, only 38% of mothers practice exclusive breastfeeding during the first six months, and 58% of mothers continue breastfeeding up to the age of two years and beyond. Breastfeeding has a numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoprolactinemia
Hypoprolactinemia is a medical condition characterized by a deficiency in the serum levels of the hypothalamic-pituitary hormone prolactin. Signs and symptoms Hypoprolactinemia is associated with ovarian dysfunction in women, and, in men, metabolic syndrome, anxiety symptoms, arteriogenic erectile dysfunction, premature ejaculation, oligozoospermia (low concentration of sperm in semen), asthenospermia (reduced sperm motility), hypofunction of seminal vesicles, and hypoandrogenism. In one study, normal sperm characteristics were restored when prolactin levels were brought up to normal values in men with hypoprolactinemia. Hypoprolactinemia can be a cause of lactation failure after childbirth. Causes Hypoprolactinemia can result from autoimmune disease, hypopituitarism, growth hormone deficiency, hypothyroidism, excessive dopamine action in the tuberoinfundibular pathway and/or the anterior pituitary, and ingestion of drugs that activate the D2 receptor, such as direct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperprolactinemia
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. Prolactin (PRL) is a peptide hormone produced by lactotroph cells in the anterior pituitary gland. PRL is involved in lactation after pregnancy and plays a vital role in breast development. Hyperprolactinemia may cause galactorrhea (production and spontaneous flow of breast milk), infertility, and disruptions in the normal menstrual period in women; as well as hypogonadism, infertility and erectile dysfunction in men. Although hyperprolactinemia can result from normal physiological changes during pregnancy and breastfeeding, it can also be caused by other etiologies. For example, high prolactin levels could result from diseas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prolactin Modulator
A prolactin modulator is a drug which affects the hypothalamic–pituitary–prolactin axis (HPP axis) by modulating the secretion of the pituitary hormone prolactin from the anterior pituitary gland. ''Prolactin inhibitors'' suppress and ''prolactin releasers'' induce the secretion of prolactin, respectively. Prolactin inhibitors Prolactin inhibitors are mainly used to treat hyperprolactinemia (high prolactin levels). Agonists of the dopamine D2 receptor such as bromocriptine and cabergoline are able to strongly suppress pituitary prolactin secretion and thereby decrease circulating prolactin levels, and so are most commonly used as prolactin inhibitors. D2 receptor agonists that are described as prolactin inhibitors include the approved medications bromocriptine, cabergoline, lisuride, metergoline, pergolide, quinagolide, and terguride and the never-marketed agent lergotrile. Other dopamine agonists and dopaminergic agents, for instance levodopa (L-DOPA), can also inhibi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasoactive Intestinal Peptide
Vasoactive intestinal peptide, also known as vasoactive intestinal polypeptide or VIP, is a peptide hormone that is vasoactive in the intestine. VIP is a peptide of 28 amino acid residues that belongs to a glucagon/secretin superfamily, the ligand of class II G protein–coupled receptors. VIP is produced in many tissues of vertebrates including the gut, pancreas, and suprachiasmatic nuclei of the hypothalamus in the brain. VIP stimulates contractility in the heart, causes vasodilation, increases glycogenolysis, lowers arterial blood pressure and relaxes the smooth muscle of trachea, stomach and gallbladder. In humans, the vasoactive intestinal peptide is encoded by the ''VIP'' gene. VIP has a half-life (t½) in the blood of about two minutes. Function In the body VIP has an effect on several tissues: In the digestive system, VIP seems to induce smooth muscle relaxation (lower esophageal sphincter, stomach, gallbladder), stimulate secretion of water into pancreatic juice a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyrotropin-releasing Hormone
Thyrotropin-releasing hormone (TRH) is a hypophysiotropic hormone produced by neurons in the hypothalamus that stimulates the release of thyroid-stimulating hormone (TSH) and prolactin from the anterior pituitary. TRH has been used clinically for the treatment of spinocerebellar degeneration and disturbance of consciousness in humans. Its pharmaceutical form is called protirelin (INN) (). Synthesis and release TRH is synthesized within parvocellular neurons of the paraventricular nucleus of the hypothalamus. It is translated as a 242-amino acid precursor polypeptide that contains 6 copies of the sequence -Gln-His-Pro-Gly-, flanked by Lys-Arg or Arg-Arg sequences. To produce the mature form, a series of enzymes are required. First, a protease cleaves to the C-terminal side of the flanking Lys-Arg or Arg-Arg. Second, a carboxypeptidase removes the Lys/Arg residues leaving Gly as the C-terminal residue. Then, this Gly is converted into an amide residue by a series of enzy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the major progestogen in the body. Progesterone has a variety of important functions in the body. It is also a crucial metabolic intermediate in the production of other endogenous steroids, including the sex hormones and the corticosteroids, and plays an important role in brain function as a neurosteroid. In addition to its role as a natural hormone, progesterone is also used as a medication, such as in combination with estrogen for contraception, to reduce the risk of uterine or cervical cancer, in hormone replacement therapy, and in feminizing hormone therapy. It was first prescribed in 1934. Biological activity Progesterone is the most important progestogen in the body. As a potent agonist of the nuclear progesterone receptor (nPR) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estradiol
Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development of female secondary sexual characteristics such as the breasts, widening of the hips and a female-associated pattern of fat distribution. It is also important in the development and maintenance of female reproductive tissues such as the mammary glands, uterus and vagina during puberty, adulthood and pregnancy. It also has important effects in many other tissues including bone, fat, skin, liver, and the brain. Though estradiol levels in males are much lower than in females, estradiol has important roles in males as well. Apart from humans and other mammals, estradiol is also found in most vertebrates and crustaceans, insects, fish, and other animal species. Estradiol is produced especially within the follicles of the ovaries, but also in o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic compound, organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 80% of the catecholamine content in the brain. It is an amine synthesized by removing a carboxyl group from a molecule of its precursor (chemistry), precursor chemical, L-DOPA, which is biosynthesis, synthesized in the brain and kidneys. Dopamine is also synthesized in plants and most animals. In the brain, dopamine functions as a neurotransmitter—a chemical released by neurons (nerve cells) to send signals to other nerve cells. Neurotransmitters are synthesized in specific regions of the brain, but affect many regions systemically. The brain includes several distinct dopaminergic pathway, dopamine pathways, one of which plays a major role in the motivational component of reward system, reward-motivated behavior. The anticipa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormone
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required for the correct development of animals, plants and fungi. Due to the broad definition of a hormone (as a signaling molecule that exerts its effects far from its site of production), numerous kinds of molecules can be classified as hormones. Among the substances that can be considered hormones, are eicosanoids (e.g. prostaglandins and thromboxanes), steroids (e.g. oestrogen and brassinosteroid), amino acid derivatives (e.g. epinephrine and auxin), protein or peptides (e.g. insulin and CLE peptides), and gases (e.g. ethylene and nitric oxide). Hormones are used to communicate between organs and tissues. In vertebrates, hormones are responsible for regulating a variety of physiological processes and behavioral activities such as diges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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