Biomaterial Database

Inhibition of hCG-stimulated adenylate cyclase in purified mouse Leydig cells by the phorbol ester PMA. 1985

A K Mukhopadhyay, and M Schumacher

The tumour-promoting phorbol ester, PMA (phorbol 12-myristate 13-acetate), markedly reduced the steroidogenic response of mouse Leydig cells to stimulation by hCG and cholera toxin. However, 8Br-cAMP-and forskolin-stimulated steroidogenesis was not inhibited by PMA. PMA did not inhibit hCG-induced steroidogenesis in the simultaneous presence of 1 microM forskolin. The analysis of intracellular cAM P indicated that the PMA-induced inhibition of steroidogenesis was the result of an impaired cAMP accumulation. Adenylate cyclase in membranes prepared from PMA-treated cells showed a diminished response to hCG, GTP, guanosine 5'-[beta, gamma-imido]triphosphate [Gpp(NH)p] or to a combination of the stimulants. PMA, however, was unable to inhibit adenylate cyclase when added directly to the membrane preparation from untreated cells. As previous observations have indicated that 125I-hCG binding and phosphodiesterase activity in mouse Leydig cells are not influenced by PMA, it is concluded from the present study that the site of inhibition has to be localised to the regulatory guanine nucleotide binding protein of the adenylate cyclase system.

UI	MeSH Term	Description	Entries
D007985	Leydig Cells	Steroid-producing cells in the interstitial tissue of the TESTIS. They are under the regulation of PITUITARY HORMONES; LUTEINIZING HORMONE; or interstitial cell-stimulating hormone. TESTOSTERONE is the major androgen (ANDROGENS) produced.	Interstitial Cells, Testicular,Leydig Cell,Testicular Interstitial Cell,Testicular Interstitial Cells,Cell, Leydig,Cell, Testicular Interstitial,Cells, Leydig,Cells, Testicular Interstitial,Interstitial Cell, Testicular
D008297	Male		Males
D010704	Phorbols	The parent alcohol of the tumor promoting compounds from CROTON OIL (Croton tiglium).	Tigliane,Tiglianes
D002772	Cholera Toxin	An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.	Cholera Toxin A,Cholera Toxin B,Cholera Toxin Protomer A,Cholera Toxin Protomer B,Cholera Toxin Subunit A,Cholera Toxin Subunit B,Choleragen,Choleragenoid,Cholera Enterotoxin CT,Cholera Exotoxin,Cholera Toxin A Subunit,Cholera Toxin B Subunit,Procholeragenoid,Enterotoxin CT, Cholera,Exotoxin, Cholera,Toxin A, Cholera,Toxin B, Cholera,Toxin, Cholera
D004224	Diterpenes	Twenty-carbon compounds derived from MEVALONIC ACID or deoxyxylulose phosphate.	Diterpene,Diterpenes, Cembrane,Diterpenes, Labdane,Diterpenoid,Labdane Diterpene,Norditerpene,Norditerpenes,Norditerpenoid,Cembranes,Diterpenoids,Labdanes,Norditerpenoids,Cembrane Diterpenes,Diterpene, Labdane,Labdane Diterpenes
D005576	Colforsin	Potent activator of the adenylate cyclase system and the biosynthesis of cyclic AMP. From the plant COLEUS FORSKOHLII. Has antihypertensive, positive inotropic, platelet aggregation inhibitory, and smooth muscle relaxant activities; also lowers intraocular pressure and promotes release of hormones from the pituitary gland.	Coleonol,Forskolin,N,N-Dimethyl-beta-alanine-5-(acetyloxy)-3-ethenyldodecahydro-10,10b-dihydroxy-3,4a,7,7,10a-pentamethyl-1-oxo-1H-naphtho(2,1-b)pyran-6-yl Ester HCl,NKH 477,NKH-477,NKH477
D006063	Chorionic Gonadotropin	A gonadotropic glycoprotein hormone produced primarily by the PLACENTA. Similar to the pituitary LUTEINIZING HORMONE in structure and function, chorionic gonadotropin is involved in maintaining the CORPUS LUTEUM during pregnancy. CG consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is virtually identical to the alpha subunits of the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity (CHORIONIC GONADOTROPIN, BETA SUBUNIT, HUMAN).	Chorionic Gonadotropin, Human,HCG (Human Chorionic Gonadotropin),Biogonadil,Choriogonadotropin,Choriogonin,Chorulon,Gonabion,Human Chorionic Gonadotropin,Pregnyl,Gonadotropin, Chorionic,Gonadotropin, Human Chorionic
D006165	Guanylyl Imidodiphosphate	A non-hydrolyzable analog of GTP, in which the oxygen atom bridging the beta to the gamma phosphate is replaced by a nitrogen atom. It binds tightly to G-protein in the presence of Mg2+. The nucleotide is a potent stimulator of ADENYLYL CYCLASES.	GMP-PNP,GMP-P(NH)P,Gpp(NH)p,Guanosine 5'-(Beta,Gamma-Imido)Triphosphate,Guanyl-5'-Imidodiphosphate,P(NH)PPG,Guanyl 5' Imidodiphosphate,Imidodiphosphate, Guanylyl
D000262	Adenylyl Cyclases	Enzymes of the lyase class that catalyze the formation of CYCLIC AMP and pyrophosphate from ATP.	Adenyl Cyclase,Adenylate Cyclase,3',5'-cyclic AMP Synthetase,Adenylyl Cyclase,3',5' cyclic AMP Synthetase,AMP Synthetase, 3',5'-cyclic,Cyclase, Adenyl,Cyclase, Adenylate,Cyclase, Adenylyl,Cyclases, Adenylyl,Synthetase, 3',5'-cyclic AMP
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