Mechanism of tho Release by Componnd 48/80 of Histamine and of a Lipid‐Soluble Smooth Muscle Stimulating Principle (“SRS”)

Abstract

Abstract. Compound 48/80 releases histamine and a lipid‐soluble smooth muscle contracting substance (“SRS”) in the perfused cat paw. The time‐course and dose‐response curves of histamine and “SRS” release were strikingly parallel. Nonspecific enzyme inhibitors such as polysaccharides and “polysalicylic acid”, and SH‐blocking agents — such as allicin and iodo‐acetate — blocked the release of both histamine and “SRS”. Heating of the paws to 45° C for 15 min had the same blocking effect. The observations support the hypothesis that compound 48/80 releases histamine in the cat paw by activating an enzymatic mechanism and that “SRS” is a product of the same or a similar mechanism.