Effect of mepyramine on the histaminase release induced by heparin injection and anaphylaxis in guinea pigs.

Injection of heparin as well as antigenic challenge in sensitized guinea pigs are known to produce a release of histaminase into the plasma. In the present study, tissue histaminase estimation was done by Spencer's method (17) and plasma estimation by Kapellar Adler's (7) method. Mepyramine pretreatment considerably decreased the histaminase release by both heparin and anaphylaxis. Mepyramine did not antagonise the anticoagulant action of heparin in vitro.