[RNA synthesis in the isolated nuclei of nerve cells treated with acetylcholine]

Acetylcholine modified the incorporation of radioactive precursors 3H-uridine-5-triphosphate, 14C-uridine and 14C-cytidine in RNA of nuclei isolated from the rat brain. This modification has two tendencies: either the activation or the suppretion. The character of the nuclear reaction depends upon the season and animal population. In the presence of actinomycin D (5.10(-5) M), acetylcholine does not influence the precursor incorporation into the nuclear RNA. In the system that involves nuclei+soluble cytoplasmic fraction acetylcholine exerts an effect that is opposite to that when the nuclei are alone. These results suggest that acetylcholine action is mediated by a cytoplasmic factor. Actinomycin D in the presence of cytoplasmic fraction did not influence effects of acetylcholine.