Administration of testosterone alleviates the constitutive sex difference in rat brain cytochrome P-450.
Sex-related difference was observed in the levels of total cytochrome P-450 (P-450) and the mono-oxygenase activity mediated by P-450(b,e), namely, aminopyrine N-demethylase and morphine N-demethylase activity in rat brain microsomes. Male rat brain had higher activity of the above enzymes as compared to the female rat brain. On the other hand, P-450(c,d) mediated 7-ethoxycoumarin O-deethylase and benzo(a)pyrene hydroxylase activity showed no sex-related difference in rat brain. Administration of testosterone elevated the levels of total P-450, aminopyrine N-demethylase and morphine N-demethylase in female rat brain to levels comparable with that of the male rat brain. No significant change was observed in the levels of 7-ethoxycoumarin O-deethylase and benzo(a)pyrene hydroxylase and NADPH cytochrome c reductase. All of the above enzyme levels were unaffected in the male rat brain following the treatment with testosterone. These results indicate that testosterone may regulate the forms of cerebral P-450 that are associated with the sex-related difference observed in rat brain.
Anandatheerthavarada
H K
HK
Department of Neurochemistry, National Institute of Mental Health and Neurosciences, Bangalore, India.
Ravindranath
V
V
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005260:Female; D008297:Male; D008861:Microsomes / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012727:Sex Characteristics; D013739:Testosterone / Q000494:pharmacology*
D013739:Testosterone; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases