Sexual difference in properties of 5 alpha-reductase in microsome of rat submandibular glands.
The properties of 5 alpha-reductase activity in the submandibular glands of rats were investigated using microsomal fraction in the presence of NADPH, and we found a sexual difference in these properties. The formation of 5 alpha-dihydrotestosterone and 5 alpha-androstane-3 alpha, 17 beta-diol from testosterone demonstrated 5 alpha-reductase in the rat microsomal fraction of this tissue sample. Apparent michaelis constants (Km) of the 5 alpha-reductase activity for testosterone was 1.02 x 10(-6) M for the female tissue. Microsomal fraction of submandibular glands of male rats had two Kms and were determined as 1.12 x 10(-6) M and 1.01 x 10(-5) M. The lower Km of 5 alpha-reductase for male rats was similar to for the females.
Department of Biochemistry, Kanagawa Dental College, Yokosuka, Japan.
S
S
Koshika
M
M
Hosaka
M
M
Tarui
M
M
Furuyama
Y
Y
Nakayama
D000818:Animals; D042944:Cholestenone 5 alpha-Reductase; D005260:Female; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008861:Microsomes / Q000201:enzymology*; D009249:NADP / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism*; D011506:Proteins / Q000302:isolation & purification; D051381:Rats; D011919:Rats, Inbred Strains; D012737:Sex Factors; D013256:Steroids / Q000302:isolation & purification; D013347:Subcellular Fractions / Q000201:enzymology; D013363:Submandibular Gland / Q000201:enzymology*; D013739:Testosterone / Q000494:pharmacology
D011506:Proteins; D013256:Steroids; D013739:Testosterone; D009249:NADP; D010088:Oxidoreductases; D042944:Cholestenone 5 alpha-Reductase