THE EFFECT OF NANDROLONE PHENYLPROPIONATE ON 14C-LEUCINE INCORPORATION INTO MUSCLE PROTEIN IN THE RAT AND RABBIT IN VIVO

Abstract

ABSTRACT Investigations have been carried out into the incorporation of 14C-leucine into muscle protein of rats and rabbits and its modification by various treatments. Significant decreases in the rate of incorporation of 14C-leucine into protein of the gastrocnemius and levator ani muscles of rats have been observed following hypophysectomy, fasting or treatment with a corticosteroid. In these situations, treatment with an anabolic steroid, nandrolone phenylpropionate, always prevented or reversed the decrease in 14C-leucine incorporation in the levator ani muscle but never in the gastrocnemius muscle. In contrast to the situation in the rat, the decreased incorporation of 14C-leucine in the gastrocnemius muscle of the rabbit following corticosteroid administration could be partially reversed by the anabolic steroid. The results demonstrate that 14C-leucine incorporation into muscle protein in vivo following various experimental treatments may vary markedly not only from one species to another but also from one muscle to another. Great care should be taken in interpreting the effect, or lack of effect, of androgenic/anabolic steroids on the basis of the response of a single muscle.