Effect of protein-synthesis inhibitors on testosterone production in rat testis interstitial tissue and Leydig-cell preparations.
Luteinizing-hormone-stimulated testosterone biosynthesis was inhibited by cycloheximide during incubation of rat testis intersitial tissue in vitro and also by puromycin and cycloheximide during incubation of Leydig-cell preparations, but not by chloramphenicol. These results suggest that a protein regualtor(s) formed by cytoplasmic protein synthesis is involved in steroidogenesis in the rat testis. The specific effect of cycloheximide and puromycin on protein synthesis rather than on other non-specific processes is suggested by the inhibition of protein synthesis and steroidogenesis with different doses of the inhibitors and the lack of effect of cycloheximide on luteinizing-hormone-induced adenosine 3':5'-cyclic monophosphate production. Stimulation of testosterone production by luteinizing hormone during superfusion of interstitial tissue was detectable within 10-20 min and reached a maximum of 120 min, and thereafter slowly decreased. Cycloheximide added at maximum steroid production caused a rapid decrease in testosterone synthesis which followed first-order kinetics (half-life 13 min), thus indicating that the protein regulator(s) has a short half-life. No effect of cycloheximide, puromycin or chloramphenicol on testosterone production in the absence of added luteinizing hormone was found, suggesting that the basal production of testosterone is independent of protein synthesis.
D000818:Animals; D002701:Chloramphenicol / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology*; D003593:Cytoplasm / Q000378:metabolism; D066298:In Vitro Techniques; D007985:Leydig Cells / Q000187:drug effects* / Q000378:metabolism; D007986:Luteinizing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008297:Male; D011691:Puromycin / Q000494:pharmacology*; D051381:Rats; D013737:Testis / Q000187:drug effects* / Q000378:metabolism; D013739:Testosterone / Q000096:biosynthesis*; D013997:Time Factors
D013739:Testosterone; D011691:Puromycin; D002701:Chloramphenicol; D007986:Luteinizing Hormone; D003513:Cycloheximide; D000242:Cyclic AMP