Histamine Release in Rabbit Blood by Simple Molecules, Inhibition and Reaction Rate Studies

Abstract

The histamine in rabbit blood-formed elements is released rapidly and completely by two types of compounds not previously reported to function as histamine-releasing agents[long dash]octadecylamine and N-(n-hexadecyl)-beta-carbomethoxy pyridinium salts. Substantial amounts of histamine may be released by as little as 3 molecules of the releasing agent per molecule of histamine liberated. The release of histamine is inhibited by compounds closely related to the releasing agents, but free histamine added with the releasing agent does not inhibit the reaction. The inhibition of histamine release by compounds closely related to the histamine releasing agents is probably competitive although the data do not fully comply with the criteria for competitive inhibition. Reaction rate studies indicate that histamine release by the above compounds does not involve enzyme action.