[Adaptation of skeletal muscle and myocardium to increased motor activity in hypo- and athyroid rats].
Changes in contractility and synthesis of protein were studied in different types of muscles of hypo- and athyroid ratts during adaptation to physical exercise. Intensity of the exercises used corresponded to metabolic power output of 70% VO2max. Thyroidectomy caused a significant decrease in Mg2+ activated actomyosin ATPase activity and in content of RNA in myocardium and in fast oxidative-glycogenolytic and glycogenolytic skeletal muscle fibers. Exercises, intensity of which corresponded to metabolic power output of 70% VO2max led to a more distinct decrease in Mg2+ activated actomyosin ATPase activity in fast glycogenolytic muscle fibers, but in fast oxidative-glycogenolytic fibers the enzymatic activity was increased up to the level comparable with that of intact animals. Rhysical working capacity of athyroid rats was lower by 40% as compared with intact trained animals. Hypothyroidism, induced by means of administration of KJ into previously trained rats, caused a decrease in physical working capacity by 25%.
D000205:Actomyosin / Q000378:metabolism; D000222:Adaptation, Physiological; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase; D004247:DNA / Q000032:analysis; D007037:Hypothyroidism / Q000503:physiopathology; D008297:Male; D009132:Muscles / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D005082:Physical Exertion; D012313:RNA / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D013963:Thyroid Hormones / Q000502:physiology*; D013965:Thyroidectomy
D013963:Thyroid Hormones; D012313:RNA; D004247:DNA; D000205:Actomyosin; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase
Adaptatsiia skeletnykh i serdechnoĭ myshts k povyshennoĭ dvigatel'noĭ aktivnosti u gipo- i atireoidnykh krys.