THE EFFECTS OF CLOSE-ARTERIAL INFUSION OF CIMATEROL INTO THE HIND-LIMB OF GROWING LAMBS

Publisher Summary This chapter describes the effects of close-arterial infusion of cimaterol into the hind-limb of growing lambs. The β-agonist cimaterol has been shown to increase the amount of lean tissue in the carcass of farm animals. The direct effects of cimaterol on hind-limb muscle metabolism were studied in growing wether lambs by close-arterially infusing either saline; a low dose of cimaterol or a high dose of cimaterol into one femoral artery for 5 days. The other leg was close-arterially infused with saline for 5 days as a control. Hind-limb muscle metabolism was studied in both limbs on day 5 of treatment. Early observations on blood flow, oxygen uptake, and carbon dioxide output across the hind-limb muscle are shown. Close-arterially infused cimaterol, at a low dose, had a local direct effect on hind-limb muscle, significantly stimulating blood flow and oxygen uptake. The other leg did not show this effect. In the high dose treatment, recirculation of the agonist appears to have occurred as shown by the increased values in both treated and saline legs compared to saline only infusions. Thus it appears that direct effects of cimaterol on muscle are important in its action.