Biomaterial Database

17 beta-Oxidation of estradiol and testosterone in the human testis. 1982

P Leinonen

The oxidation of 17 beta-estradiol in the human testis was studied in order to characterize a potentially important regulatory step in the action of estradiol in the human testis. 17 beta-Estradiol was shown to be converted to estrone, a weaker estrogen, in a reaction which was not inhibited by testosterone to any greater extent. When compared with the corresponding 17 beta-oxidation of testosterone, differences in coenzyme preferences, hydrogen ion sensitivity and inhibitions by estradiol and testosterone were observed, suggesting to a presence of different 17 beta-hydroxysteroid dehydrogenases in the human testis. Thus the human testis may counteract some of the deleterious effects of 17 beta-estradiol on androgen biosynthesis by metabolizing it to a weaker estrogen, in a reaction which probably is not inhibited by high testicular testosterone concentrations.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D009249	NADP	Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)	Coenzyme II,Nicotinamide-Adenine Dinucleotide Phosphate,Triphosphopyridine Nucleotide,NADPH,Dinucleotide Phosphate, Nicotinamide-Adenine,Nicotinamide Adenine Dinucleotide Phosphate,Nucleotide, Triphosphopyridine,Phosphate, Nicotinamide-Adenine Dinucleotide
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D004958	Estradiol	The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids.	17 beta-Estradiol,Estradiol-17 beta,Oestradiol,17 beta-Oestradiol,Aerodiol,Delestrogen,Estrace,Estraderm TTS,Estradiol Anhydrous,Estradiol Hemihydrate,Estradiol Hemihydrate, (17 alpha)-Isomer,Estradiol Monohydrate,Estradiol Valerate,Estradiol Valeriante,Estradiol, (+-)-Isomer,Estradiol, (-)-Isomer,Estradiol, (16 alpha,17 alpha)-Isomer,Estradiol, (16 alpha,17 beta)-Isomer,Estradiol, (17-alpha)-Isomer,Estradiol, (8 alpha,17 beta)-(+-)-Isomer,Estradiol, (8 alpha,17 beta)-Isomer,Estradiol, (9 beta,17 alpha)-Isomer,Estradiol, (9 beta,17 beta)-Isomer,Estradiol, Monosodium Salt,Estradiol, Sodium Salt,Estradiol-17 alpha,Estradiol-17beta,Ovocyclin,Progynon-Depot,Progynova,Vivelle,17 beta Estradiol,17 beta Oestradiol,Estradiol 17 alpha,Estradiol 17 beta,Estradiol 17beta,Progynon Depot
D004970	Estrone	An aromatized C18 steroid with a 3-hydroxyl group and a 17-ketone, a major mammalian estrogen. It is converted from ANDROSTENEDIONE directly, or from TESTOSTERONE via ESTRADIOL. In humans, it is produced primarily by the cyclic ovaries, PLACENTA, and the ADIPOSE TISSUE of men and postmenopausal women.	Folliculin (Hormone),Estrone, (+-)-Isomer,Estrone, (8 alpha)-Isomer,Estrone, (9 beta)-Isomer,Estrovarin,Kestrone,Unigen,Wehgen
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000735	Androstenedione	A delta-4 C19 steroid that is produced not only in the TESTIS, but also in the OVARY and the ADRENAL CORTEX. Depending on the tissue type, androstenedione can serve as a precursor to TESTOSTERONE as well as ESTRONE and ESTRADIOL.	4-Androstene-3,17-dione,delta-4-Androstenedione,4 Androstene 3,17 dione,delta 4 Androstenedione
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
D013739	Testosterone	A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.	17-beta-Hydroxy-4-Androsten-3-one,17-beta-Hydroxy-8 alpha-4-Androsten-3-one,8-Isotestosterone,AndroGel,Androderm,Andropatch,Androtop,Histerone,Sterotate,Sustanon,Testim,Testoderm,Testolin,Testopel,Testosterone Sulfate,17 beta Hydroxy 4 Androsten 3 one,17 beta Hydroxy 8 alpha 4 Androsten 3 one,8 Isotestosterone