Free intracellular and protein bound amino acids in tissues as affected by a mixed beta-adrenergic agonist.

The administration of metaproterenol induced an increase in gastrocnemius muscle weight without change in body growth rate or tissue protein concentrations, while epididymal fat was reduced. This effect was accompanied by an enhancement in the levels of intracellular amino acids in muscle. By contrast, liver amino acids were unaffected by treatment with the mixed beta-adrenergic agonist.