A new method of testing anti-allergic drugs.

Rats were sensitized with a single intraperitoneal dose of bovine serum albumin in alhydrogel plus Bordetella pertussis vaccine, and local anaphylaxis was elicited in the paw by soluble antigen 2 weeks later. The response was mainly due to IgE-type antibodies and proved to be highly sensitive to beta-adrenoceptor agonists. Dexamethasone inhibited the response after a lag phase. Methysergide, disodium chromoglycate, diethylcarbamazine, BW 775/c, nordihydroguarjaretic acid, and FPL 55712 were also suppressive, while mepyramine was without effect. A synergism between methysergide and FPL 55712 was shown. Active local paw anaphylaxis appears to be adequate and easily applicable for large-scale screening of anti-allergic drugs.