Abstract
Incubation of cultured mouse neuroblastoma cells with histamine caused a rapid and marked increase in the formation of guanosine 3',5'-monophosphate (cyclic GMP) by these cells. Receptor agonists for H1, but not H2, caused this effect which was reduced by H1 but not by H2 or muscarinic acetylcholine receptor antagonists. These results indicate that activation of H1 receptors in these cultured nerve cells stimulated cyclic GMP formation.