EFFECT OF TESTOSTERONE ON PROTEIN SYNTHESIS AND CONTRACTILITY OF THE LEVATOR ANI MUSCLE OF THE RAT

Abstract

SUMMARY The effects of testosterone on the incorporation of leucine and uridine into the proteins and RNA in vitro and on contractile properties of the levator ani muscle were studied. After long-term preincubation of the muscle with testosterone, incorporation of the labelled precursors into RNA and proteins of the muscle increased by 33 and 78% respectively. No previous treatment in vivo was necessary to show this effect of testosterone. The increase of incorporation of the labelled precursors into RNA and proteins, tested after preincubation with testosterone, was more pronounced after castration, and was 61 and 134% respectively. The incorporation of labelled precursors into RNA and proteins of the diaphragm muscle of the rat was not affected by preincubation with testosterone in vitro. Long-term application of testosterone in vitro resulted in a decrease of contraction time and latency period of the levator ani muscle.