EFFECT OF CLENBUTEROL ON RECOVERY OF MUSCLE MASS AND CARCASS PROTEIN-CONTENT FOLLOWING EXPERIMENTAL HYPERTHYROIDISM IN OLD RATS

The beta(2)-adrenoceptor agonist, clenbuterol, has hastened the recove ry of skeletal muscle and carcass weights and carcass protein stores l ost during experimental hyperthyroidism in 24-month-old rats. Daily in jection of 6.5 mu g T-3 per 100 g body weight for 2 weeks and 4.0 mu g for the third week caused a 17-22% reduction in total body, carcass a nd combined hindlimb muscle weights, and a 16-21% reduction in carcass protein stores. Feeding diet containing 10 mg clenbuterol per kg duri ng a 3-week recovery period caused complete restoration of these param eters to euthyroid control levels while the feeding control diet did n ot.