The catabolic effect of glucocorticoids on different types of skeletal muscle fibres and its dependence upon muscle activity and interaction with anabolic steroids.
Myofibrillar protease activity was found to be elevated, and content of RNA and DNA reduced in m. quadriceps femoris, especially in the fast-twitch white fibers, after dexamethasone treatment. Moderate physical activity prevents, to some extent, the effect of synthetic glucocorticoids. Exhaustive exercise augments the myofibrillar protease activity in both types of muscle fibers. The fast-twitch white type of muscle fibers in exhausted rats are found to have an elevated anticatabolic activity after the treatment of rats with anabolic steroid. It appears that there exists a close correlation between myofibrillar protease activity and muscle weight in the fast-twitch white fibers in dexamethasone treated and exhausted rats.
D045930:Anabolic Agents / Q000494:pharmacology*; D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology; D004347:Drug Interactions; D005938:Glucocorticoids / Q000494:pharmacology*; D008297:Male; D009132:Muscles / Q000187:drug effects* / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D010447:Peptide Hydrolases / Q000378:metabolism; D005082:Physical Exertion; D051381:Rats; D011919:Rats, Inbred Strains
D045930:Anabolic Agents; D005938:Glucocorticoids; D003907:Dexamethasone; D010447:Peptide Hydrolases