[Various adrenergic reactions in experimental hyperthyroidism]

Three adrenergic responses, i. e. noradrenaline calorigenic effect, positive isoproterenol chronotropic action and seminiferous duct contraction after noradrenaline use was studied in experimental albino male rats. It was shown that hyperthyroidism provokes intensification of the beta-adrenergic responses examined (noradrenaline calorigenic effect and positive isoproterenol chronotropic effect); beta-adrenoreceptor sensitivity remained unchanged. Experimental hyperthyroidism was accompanied by a decrease in alpha1-adrenoreceptor sensitivity without changing the intensity of this adrenergic response.