Inhibition by nicotinamide of an homologous PCA reaction and antigen-induced histamine release from rat peritoneal mast cells.

The antigen-induced release of histamine both in vitro from rat peritoneal cell suspensions containing mast cells actively sensitized with IgE antibody and in vivo from passively sensitized skin can be inhibited by relatively high doses of nicotinamide. The action of nicotinamide on the cellular mechanism involved in the regulation of antigen-induced histamine release is discussed.