The activity of 3 alpha- and 3 beta-hydroxysteroid dehydrogenases and 5 alpha-reductase, together with androgen levels in male rat pituitary during sexual maturation.
In all subcellular pituitary fractions, 3 alpha-hydroxysteroid dehydrogenase (3 alpha-ol dehydrogenase) activity is high (1 to 3 pmol/mg/h) with NADH or NADPH as cofactor, and 3 beta-hydroxysteroid dehydrogenase (3 beta-ol dehydrogenase) activity much lower. The highest activity of the latter (0.15 pmol/mg/h) is detected in cytosol with NADH as cofactor. During sexual maturation, cytosolic (NADH-dependent) 3 alpha- and 3 beta-ol dehydrogenase activities remain constant, whereas the 5 alpha-reductase activity is maximum at 37 days. The levels of different pituitary androgens were evaluated by radioimmunoassay. At 28 days, testosterone level is 4 ng/g of tissue, then after 42 days the level remains between 4.5 and 6 ng/g at a level higher than the DHT level. In all cases during the maturation of the rat, the different 5 alpha-reduced androgens are in the same ratio: DHT greater than 3 alpha-diol greater than 3 beta-diol, and the sum of these three 5 alpha-reduced androgens decreases between the 28th and the 90th day.
Ducouret
B
B
Laboratoire de Biologie Moléculaire, U.A. C.N.R.S., Rennes, France.
Valotaire
Y
Y
D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000728:Androgens / Q000032:analysis*; D015113:Androstane-3,17-diol / Q000032:analysis; D000818:Animals; D042944:Cholestenone 5 alpha-Reductase; D013196:Dihydrotestosterone / Q000032:analysis; D008297:Male; D008861:Microsomes / Q000201:enzymology; D009243:NAD / Q000502:physiology; D009249:NADP / Q000502:physiology; D010088:Oxidoreductases / Q000378:metabolism*; D010902:Pituitary Gland / Q000032:analysis / Q000201:enzymology*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D012741:Sexual Maturation; D013739:Testosterone / Q000032:analysis; D013997:Time Factors
D000728:Androgens; D013196:Dihydrotestosterone; D009243:NAD; D015113:Androstane-3,17-diol; D013739:Testosterone; D009249:NADP; D010088:Oxidoreductases; D015096:3-Hydroxysteroid Dehydrogenases; D042944:Cholestenone 5 alpha-Reductase