[Intracellular influence of different mediators on acid ribonuclease activity in brain tissue].

The effect of acetylcholine, norepinephrine, serotonin, GABA and histone preparations on nervous tissue acid ribonuclease activity has been studied. Acetylcholine and serotonin in vitro were found to reduce the leakage of this enzyme out of lysosomes, whereas norepinephrine and histones enhanced it. These agents did not change free acid ribonuclease activity. It is assumed that these neurotransmitters and histones can take part in the regulation of intracellular RNA metabolism in brain tissue by changing the amount of the free acid ribonuclease fraction through affecting lysosome membranes rather than the activity of the free enzyme. GABA changes neither enzyme leakage out of lysosomes nor its activity.