Myosin synthesis and enzymatic properties during thyroxine intoxication in rabbits.
Hyperthyroidism has been induced to rabbits by a daily subcutaneous injection of D-L thyroxine (0.3 mg/kg). The ventricular myosin Ca2+ ATPase was increased after one week and reached + 100 % after two weeks while the K+ EDTA ATPase remained normal. During the same period, the heart weight, and the myosin incorporation of 3H-lysine after a four hour period of labelling had increased in parallel. The enhancement of both the Ca2+ ATPase and the labelling of myosin correlate, which suggests the appearance of a new molecule during the course of intoxication. This biochemical abnormality was unchanged after treatment with propranolol.
D000818:Animals; D001835:Body Weight; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D006332:Cardiomegaly / Q000378:metabolism; D006339:Heart Rate; D006980:Hyperthyroidism / Q000378:metabolism*; D008297:Male; D008970:Molecular Weight; D009206:Myocardium / Q000378:metabolism*; D009218:Myosins / Q000096:biosynthesis / Q000378:metabolism*; D011433:Propranolol / Q000494:pharmacology; D011817:Rabbits
D011433:Propranolol; D009218:Myosins; D000252:Calcium-Transporting ATPases