Cutaneous Responses to Allergen after Local Pretreatment with Beta-Adrenoceptor Stimulating and Blocking Agents

Abstract

.beta.-Adrenoceptor stimulating agents possess anti-allergic effects in vitro and in vivo. To further study the mechanism of action, the effects on allergen-induced cutaneous reactions of intradermally (i.d.) injected prenalterol (1-10 .mu.g), terbutaline (2.5-250 ng) and KWD 2131 (100 mg-2.5 .mu.g) [i.e., compounds with preferential actions on .beta.1-, .beta.2-adrenoceptors and on .beta.-adrenoceptors not fitting this classification] were compared in 10 atopic subjects. All injections were given according to a double-blind design. Terbutaline and KWD 2131 [(1-(3,5-dihydroxyphenyl)-2-(1,1-dimethyl-2-hydroxyethyl)-amino) ethanol sulfate] produced a dose-dependent inhibition of the skin reactions induced by injecting horse dander allergen 5 min later. Terbutaline was about 20 times as potent as KWD 2131, whereas prenalterol was inactive. Propranolol fully blocked the anti-allergic effect produced by terbutaline. The cutaneous anti-allergic effect of .beta.-adrenoceptor-stimulating drugs is mediated via activation of .beta.2 adrenoceptors, possibly on the mast cell, resulting in inhibition of mediator release.