Temperature modulation of α‐ and β‐adrenoceptors in the isolated frog heart

Abstract

. The effects of adrenaline on the isolated frog's heart at 27° C are not antagonized by phentolamine (1·5 × 10−6m) but are abolished at 7° C. . At 27° C isoprenaline was more potent than noradrenaline, but at 7° C noradrenaline was more potent than isoprenaline. . Phenoxybenzamine (1·5 × 10−5m) or dibenamine (1·5 × 10−5m) at 7° C abolished the work output induced by adrenaline. When the temperature was raised to 24° C., adrenaline caused an increase in work output. . It is concluded that in the isolated frog heart there are at least two pools of adrenoceptors, the availability of which can be governed by temperature. 1970 British Pharmacological Society