Temperature dependence of catecholamine depletion by reserpine in the heart of the toad (Bufo marinus)

1. The catecholamines in toad ventricle were adrenaline (90%) and noradrenaline (10%); there was no dopamine.2. Phenoxybenzamine and tyramine stimulated the isolated heart and reduced the catecholamine content.3. Reserpine treatment of toads kept at 20 degrees C did not affect the adrenaline but reduced the noradrenaline content of the ventricle.4. At 37 degrees C, reserpine caused depletion of both adrenaline and noradrenaline, and the stimulant actions of phenoxybenzamine and tyramine were lost.