Growth hormone regulates expression of rat liver cytochrome P-450 15 beta at a pretranslational level.
Polyclonal antibodies to rat liver microsomal cytochrome P-450 15 beta-hydroxylase were used to screen a female rat liver cDNA expression library. Recombinant plasmid C-6, isolated from a positive colony, contained a cDNA of 1000 base pairs which hybridized to a single, 1.7 kilobase class of mRNA on Northern blot analysis. Semi-quantitative slot blots showed that the level of this mRNA was 17-fold lower in male rat liver than in females. Continuous infusion of human growth hormone to male rats caused them to express female levels of C-6 mRNA, while the same daily dose of hormone given intermittently had no effect. A high degree of correlation of the levels of C-6 mRNA with 15 beta-hydroxylase protein levels and catalytic activities was found, demonstrating that the sexually differentiated, growth hormone-dependent expression of the 15 beta-hydroxylase is regulated at a step preceding translation.
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D004334:Drug Administration Schedule; D004963:Estrenes / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D013006:Growth Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D007016:Hypophysectomy; D008099:Liver / Q000502:physiology; D008297:Male; D015741:Metribolone; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D012723:Sex; D013250:Steroid Hydroxylases / Q000235:genetics*
D004963:Estrenes; D012333:RNA, Messenger; D015741:Metribolone; D013006:Growth Hormone; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D001189:Aryl Hydrocarbon Hydroxylases; C034694:steroid 15-beta-hydroxylase