||Sexual Patterns of Monooxygenase Function in the Liver of Marine Teleosts and the Regulation of Activity by Estradiol.
Gray, E. S. ;
||Woods Hole Oceanographic Institution, MA. ;Massachusetts Inst. of Tech., Cambridge.;Environmental Protection Agency, Washington, DC.;National Institutes of Health, Bethesda, MD.;National Science Foundation, Washington, DC.
||WHOI-88-34; EPA-CX81-356701 ;EPA-CR81-315501;
Marine fishes ;
Cytochrome P-450 ;
Enzyme activation ;
Sex factors ;
Pseudopleuronectes americanus ;
||Some EPA libraries have a fiche copy filed under the call number shown.
||Sex differences in hepatic microsomal cytochrome P-450 and monooxygenase activities were investigated in the marine teleosts scup (Stenotomus chrysops) and winter flounder (Pseudopleuronectes americanus). Sex differences in ethoxyresorufin O-deethylase activity reflected suppressed levels of the responsible isozyme, P-450E, in females. Microsomal estradiol (E(2)) 2-hydroxylase activity, demonstrated here for the first time in teleosts, was sexually differentiated in scup, and P-450-mediated although not by P-450E. E(2)2-hydroxylase, testosterone 6(beta)-hydroxylase, and aminopyrine N-demethylase activities were sexually differentiated in winter flounder, and in both species these activities were correlated to some extent with isozyme P-450A levels, suggesting co-regulation with or catalysis by P-450A. Altered microsomal monooxygenases in gonadally mature females accounted for several sex differences in metabolism, implying monooxygenase regulation by E(2). In immature winter flounder, E(2) injections shifted some microsomal activities and enzyme levels toward female-type patterns. This suggested that E(2) can regulate monooxygenase activities in winter flounder, and that additional factors regulate individual cytochrome P-450 isozymes in adult females.
||Sponsored in part by grant NSF-OCE83-10505. Prepared in cooperation with Massachusetts Inst. of Tech., Cambridge. Sponsored by Environmental Protection Agency, Washington, DC., National Institutes of Health, Bethesda, MD., and National Science Foundation, Washington, DC.
|NTIS Title Notes
||PC A08/MF A01