Noradrenalin as a regulator of RNA and Na,K-ATPase synthesis in nerve cells

Conclusions

• 1. Noradrenalin inhibits RNA synthesis in isolated neuronal nuclei; in the presence of soluble cytoplasmic fraction, noradrenalin activates RNA synthesis. Similar results were obtained with adenosine-3′,5′-cyclophosphate, which indicates that the cytoplasm contains factors that control the effects of these agents.

• 2. In a cell-free system containing neuronal nuclei and a microsomal cytoplasmic fraction, noradrenalin inhibits the synthesis of Na,K-ATPase, its action being directed at the inhibition of RNA synthesis on DNA of the Na, K-ATPase gene. Adenosine-3′,5′-cyclophosphate and dopamine have no effect on the synthesis of Na,K-ATPase in a cell-free system.

• 3. Noradrenalin has no effect on RNA and DNA synthesis in glia cells.

• 4. These results indicate that some neuronal genes are subject to noradrenalin control; the expression of some of these is activated, while that of others is inhibited. Judging from the effect of noradrenalin on total RNA synthesis, the number of activated genes is greater than that of inhibited genes.