Immunopharmacological studies on mydocalm and related compounds as an antagonist of slow reacting substance of anaphylaxis (SRS-A).

The antagonistic effect of 2,4'-dimethyl-3-piperidino propiophenone hydrochloride (Mydocalm) and its 15 derivatives against the activity of slow reacting substance of anaphylaxis (SRS-A) were examined in vitro. Mydocalm, 2-methyl-3-piperidino-beta-propionaphthone hydrochloride (As-5) and 2,3',4'-trimethyl-3 piperidinopropiophenone hydrochloride (As-14) were found to be potent antagonists to SRS-A. The above three compounds inhibited homologous passive cutaneous anaphylaxis (PCA) in rats and guinea pigs but not heterologous PCA in guinea pigs. As-5 inhibited the release of histamine from and the degranulation of rat mesenterium mast cells. As-14 also showed the inhibition of the degranulation. Mydocalm, however, showed no inhibition of these reactions. Experimental asthma in guinea pigs which were passively sensitized with guinea pig immunoglobulin E antibody was significantly inhibited by p.o. administration of Mydocalm, As-5 or As-14 respectively.