[Effect of cycloheximide on synthesis of skeletal muscle proteins and nuclear DNA-dependent RNA-polymerase activity].
A high sensitivity towards cycloheximide is shown for three main protein fractions of albino rat skeletal muscle, i. e. a 50% inhibition of myofibrillar protein synthesis is caused by a dose of 0.1 mg/100 g of body weight after 3.5 h, the rate of inhibition of two other fractions is even higher. A dose of 3.0 mg/100 g of body weight inhibits the synthesis of the sarcoplasmic and myofibrillar proteins by 96% by the end of the 15th minute. Administration of cycloheximide in vivo (0.3 mg/100 g of body weight) inhibits the alpha-amanitin-resistant DNA-dependent RNA-polymerase activity of the nuclei. The relation between the inhibition rate and time of the cycloheximide action is ruled by the first order kinetic. This allows postulating the existence of a fast renewal with a period of half-life of about 110 min (determined graphically) among nuclear proteins involved in the transcription of rRNA. The idea of this protein participation in adaptive shifts of rRNA synthesis in the systematic skeletal muscle function is suggested.
D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D009124:Muscle Proteins / Q000096:biosynthesis*; D009210:Myofibrils / Q000187:drug effects / Q000378:metabolism; D012318:RNA Polymerase I / Q000037:antagonists & inhibitors; D051381:Rats; D014158:Transcription, Genetic / Q000187:drug effects
D009124:Muscle Proteins; D003513:Cycloheximide; D012321:DNA-Directed RNA Polymerases; D012318:RNA Polymerase I
Sintez belkov skeletnykh myshts i DNK-zavisimiia RNK-polimeraznaia aktivnost' iader pri deistvii tsiklogeksimida.