[Desensitization of the alpha 1-adrenergic reaction under the action of noradrenaline in increasing concentrations].

The kinetics of alpha 1-adrenergic response to noradrenaline in a wide range of concentrations upon the cumulative and discrete addition of noradrenaline, was studied in isolated epididymal sections of the rat vas deferens. Two pools of alpha 1-adrenoceptors differing in their affinity to noradrenaline were revealed in both cases. The desensitisation of both pools of alpha 1-adrenoceptors is shown during the adrenergic reaction upon the cumulative addition of noradrenaline. The desensitisation is expressed in the decrease of the number of active receptors.