HOMEORHETIC CHANGES PRODUCED BY A BETA-AGONIST ON ADIPOSE AND MUSCLE TISSUES IN RAT

A repartitioning effect was observed in young rats after a chronic treatment with a non-selective beta-agonist administered subcutaneously. An increase in carcass protein (P < 0.05) accompanied by a reduction in fat stores (P < 0.01) and an increase in back fat oxygen consumption (P < 0.05) were found in treated animals. The muscle mass accretion should be attributed to a reduction in muscle protein degradation, based on lower activity of the proteolytic enzyme cathepsin A in treated rats, rather than to changes in protein synthesis, assessed by an amino-acid incorporation technique. The anabolic actions of this compound apparently involve changes in muscle prostaglandine E2 and reduction-oxidation state.