Biomaterial Database

Effect of testosterone on hypothalamic LH-RH content. 1976

S H Shin, and C J Howitt

Hypothalamic LH-RH content in male rats is lowered after castration. The s.c. implantation of testosterone or testosterone propionate-packed Silastic tubing (from 0.5 to 6 cm in length) in a range which encompassed the normal circulating plasma testosterone concentration, prevented this lowered LH-RH content 21 days following castration and simultaneous implantation. The temporal response to implanted testosterone was then studied: rats were killed 1,2,4,8,14 and 21 days after castration and simultaneous implantation of 3 cm testosterone-packed Silastic tubing. The hypothalamic LH-RH content began to decrease in the castrated group after 4 days and fell progressively thereafter. However, the hypothalamic LH-RH content of the castrated group maintained with constant levels of testosterone showed no such reduction at any time following castration. These experiments indicate that circulating testosterone in physiological concentrations can maintain a normal hypothalamic LH-RH content and demonstrate an action of testosterone, in physiological concentrations, in the feedback regulation of LH-RH secretion.

UI	MeSH Term	Description	Entries
D007031	Hypothalamus	Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.	Lamina Terminalis,Preoptico-Hypothalamic Area,Area, Preoptico-Hypothalamic,Areas, Preoptico-Hypothalamic,Preoptico Hypothalamic Area,Preoptico-Hypothalamic Areas
D007986	Luteinizing Hormone	A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.	ICSH (Interstitial Cell Stimulating Hormone),Interstitial Cell-Stimulating Hormone,LH (Luteinizing Hormone),Lutropin,Luteoziman,Luteozyman,Hormone, Interstitial Cell-Stimulating,Hormone, Luteinizing,Interstitial Cell Stimulating Hormone
D007987	Gonadotropin-Releasing Hormone	A decapeptide that stimulates the synthesis and secretion of both pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE. GnRH is produced by neurons in the septum PREOPTIC AREA of the HYPOTHALAMUS and released into the pituitary portal blood, leading to stimulation of GONADOTROPHS in the ANTERIOR PITUITARY GLAND.	FSH-Releasing Hormone,GnRH,Gonadoliberin,Gonadorelin,LH-FSH Releasing Hormone,LHRH,Luliberin,Luteinizing Hormone-Releasing Hormone,Cystorelin,Dirigestran,Factrel,Gn-RH,Gonadorelin Acetate,Gonadorelin Hydrochloride,Kryptocur,LFRH,LH-RH,LH-Releasing Hormone,LHFSH Releasing Hormone,LHFSHRH,FSH Releasing Hormone,Gonadotropin Releasing Hormone,LH FSH Releasing Hormone,LH Releasing Hormone,Luteinizing Hormone Releasing Hormone,Releasing Hormone, LHFSH
D008297	Male		Males
D010903	Pituitary Gland, Anterior	The anterior glandular lobe of the pituitary gland, also known as the adenohypophysis. It secretes the ADENOHYPOPHYSEAL HORMONES that regulate vital functions such as GROWTH; METABOLISM; and REPRODUCTION.	Adenohypophysis,Anterior Lobe of Pituitary,Anterior Pituitary Gland,Lobus Anterior,Pars Distalis of Pituitary,Adenohypophyses,Anterior Pituitary Glands,Anterior, Lobus,Anteriors, Lobus,Lobus Anteriors,Pituitary Anterior Lobe,Pituitary Glands, Anterior,Pituitary Pars Distalis
D002369	Castration	Surgical removal or artificial destruction of gonads.	Gonadectomy,Castrations,Gonadectomies
D004343	Drug Implants	Small containers or pellets of a solid drug implanted in the body to achieve sustained release of the drug.	Drug Implant,Drug Pellet,Pellets, Drug,Drug Pellets,Implant, Drug,Implants, Drug,Pellet, Drug
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012826	Silicone Elastomers	Polymers of silicone that are formed by crosslinking and treatment with amorphous silica to increase strength. They have properties similar to vulcanized natural rubber, in that they stretch under tension, retract rapidly, and fully recover to their original dimensions upon release. They are used in the encapsulation of surgical membranes and implants.	Elastomers, Silicone,Rubber Silicone,Silicone Rubber,Elastosil,Microfil,SE-30,Elastosils,Microfils,SE 30,SE30,Silicone Elastomer
D013737	Testis	The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.	Testicles,Testes,Testicle