Pretranslational regulation of alpha 2u-globulin in rat liver by growth hormone.
Hypophysectomy is known to cause complete suppression of the hepatic synthesis alpha 2u-globulin. The effect of hypophysectomy on the synthesis of alpha 2u-globulin can be reversed by multiple hormone treatment. The role of pituitary growth hormone in the multihormonal regulation of alpha 2u-globulin in rat liver was examined in the hypophysectomized male rats with and without growth hormone supplementation. Daily treatment of hypophysectomized rats with 5 alpha-dihydrotestosterone, corticosterone, thyroxine, and growth hormone for 8 days caused about 80% recovery in the hepatic content of alpha 2u-globulin and its corresponding mRNA as determined by radioimmunoassay, in vitro translation, and liquid hybridization with a cloned cDNA probe. However, omission of growth hormone from the treatment regimen failed to raise hepatic alpha 2u-globulin and its mRNA to more than 5% of the normal control. The possible effect of growth hormone on the translation of the mRNA for alpha 2u-globulin was examined with cultured hepatocytes derived from growth hormone-deficient rats. Culture of these cells in the presence of growth hormone for 24 h did not turn on the synthesis of alpha 2u-globulin. These results indicate that growth hormone regulates the synthesis of alpha 2u-globulin by acting at a step antecedent to mRNA translation.
D000510:Alpha-Globulins / Q000235:genetics*; D000818:Animals; D002478:Cells, Cultured; D003345:Corticosterone / Q000494:pharmacology; D013196:Dihydrotestosterone / Q000494:pharmacology; D013006:Growth Hormone / Q000494:pharmacology*; D007016:Hypophysectomy; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D011061:Poly A / Q000235:genetics; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D013974:Thyroxine / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects*
D000510:Alpha-Globulins; D012333:RNA, Messenger; C013803:alpha 2u globulin; D013196:Dihydrotestosterone; D011061:Poly A; D013006:Growth Hormone; D013974:Thyroxine; D003345:Corticosterone