Gonadotropin Releasing Hormone (GnRH) is a peptide hormone responsible for the release of FSH and LH from the anterior pituitary. GnRH is synthesized and released by the hypothalamus. Peptides are the family of molecules formed from the linking, in a defined order, of various amino acids. ... Hormone is also the NATO reporting name for the Soviet/Russian Kamov Ka-25 military helicopter. ... Follicle stimulating hormone (FSH) is a hormone produced by gonadotropes in the anterior pituitary gland. ... Luteinizing hormone (LH) is a hormone released by gonadotropes in the anterior lobe of the pituitary gland. ... The anterior pituitary (also called the adenohypophysis) comprises the anterior lobe of the pituitary gland and is part of the endocrine system. ... In the anatomy of mammals, the hypothalamus is a region of the brain located below the thalamus, forming the major portion of the ventral region of the diencephalon and functioning to regulate certain metabolic processes and other autonomic activities. ...

Gene

The gene for the GnRH precursor is located on chromosome 8. This precursor contains 92 amino acids and is processed to GnRH, a decapeptide (10 amino acids). This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... Figure 1: Chromosome. ...

Structure

The identity of GnRH was clarified by the 1977 Nobel Laureates Roger Guillemin and Andrew V. Schally: pyroGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly CONH2. For the album by Ash, see 1977 (album). ... The Nobel Prizes (pronounced no-BELL or no-bell) are awarded annually to people who have done outstanding research, invented groundbreaking techniques or equipment, or made outstanding contributions to society. ... Andrzej Wiktor Schally (born November 20, 1926) in Wilno, Poland), is a Polish endocrinologist and Nobel Prize winner in 1977 in Medicine for research work. ...

GnRH as a neurohormone

GnRH is considered a neurohormone, a hormone produced in a specific neural cell and released at its neural terminal. A key area for production of GnRH in the hypothalamus is the arcuate nucleus. GnRH is transported in the portal bloodstream to the target, the gonadotropes, and activates receptors in the cell wall. GnRH is degradated by proteolysis within a few minutes. Any hormone produced by neurosecretory cells, usually in the brain. ... The arcuate nucleus is a collection of neurons present in the hypothalamus. ... Gonadotropes are cells in the anterior pituitary which produce the gonadotropins luteinizing hormone or follicle-stimulating hormone. ... Receptor may refer to: In telecommunication, a receiver. ... A cell wall is a more or less solid layer surrounding a cell. ... Proteolysis is the directed degradation (digestion) of proteins by cellular enzymes called proteases or by intramolecular digestion. ...

Control of FSH and LH

In the pituitary GnRH stimulates synthesis and release of FSH and LH, a process that is controlled by the frequency and amplitude of GnRH pulses, as well as the feedback of androgens and estrogens. Thus a single hormone, GnRH, controls a complex process of follicular growth, ovulation, and corpus luteum maintenance in the female, and spermatogenesis in the male. This process utilizes feedback loops to regulate GnRH pulse activity. Androgen is the generic term for any natural or synthetic compound, usually a steroid hormone, that stimulates or controls the development and maintenance of masculine characteristics in vertebrates. ... Estrogens (or oestrogens) are a group of steroid compounds that function as the primary female sex hormone. ...

Activity

GnRH activity is very low during childhood. During the reproductive years pulse activity is critical for successful reproductive function as controlled by feedback loops. However, once a pregnancy is established GnRH activity is not required. Pulse activity can be disrupted by hypothalamic-pituitary disease, either dysfunction (i.e hypothalamic suppression) or organic lesions (trauma, tumor). Elevated prolactin levels decrease GnRH activity. In contrast hyperinsulinemia increases pulse activity leading to disordery LH and FSH activity as seen in PCOS. GnRH formation is congenitally absent in Kallmann syndrome. Dopamine appears to decrease GnRH activity. A male Caucasian toddler child A child (plural: children) is a young human. ... Prolactin is a hormone secreted by lactotropes in the adenohypophysis (anterior pituitary gland) which is made up of 199 amino acids with a molecular weight of about 23,000 daltons. ... The structure of insulin Red: carbon; green: oxygen; blue: nitrogen; pink: sulfur. ... Polycystic ovary syndrome (PCOS, also known clinically as Stein-Leventhal syndrome), is an endocrine disorder that affects 5–10% of women. ... Kallmann syndrome is an example of hypogonadism (decreased functioning of the sex hormone-producing glands) caused by a deficiency of gonadotropin-releasing hormone (GnRH), which is created by the hypothalamus. ... Dopamine is a neurotransmitter in the brain. ...

GnRH in other organs

GnRH is found in organs outside of the hypothalamus and pituitary and its role in other life processes is poorly understood. For instance, there is likely to be a role for GnRH in the placenta and in the gonads. The placenta is an ephemeral (temporary) organ present only in female placental mammals during gestation (pregnancy). ... A sex organ, or primary sexual characteristic, narrowly defined, is any of those parts of the body (which are not always bodily organs according to the strict definition) which are involved in sexual reproduction and constitute the reproductive system in an complex organism; namely: Male: penis (notably the glans penis...

Agonists and antagonists

While GnRH has been synthesized and become available, its short half life requires infusion pumps for its clinical use. Modifications of the decapeptide structure of GnRH have led to analog medications that either stimulate (GnRH agonists) or suppress (GnRH antagonists) the gonadotropins. Importantly, through downregulation agonists are also able to exert a prolonged suppression effect. An infusion pump or perfusor infuses fluids, medication or nutrients into a patients circulatory system. ... A GnRH agonist is a synthetic peptide that acts like the gonadotropin releasing hormone (GnRH) but has a much longer biological half life. ... Downregulation is the process by which a cell decreases the number of receptors to a given hormone or neurotransmitter to reduce its sensitivity to this molecule. ...