[Adrenergic regulation and adrenoreactivity of the rat heart during adaptation to altitude hypoxia].

Male albino rats were adapted to 6 km "altitude" in barocamber. Responses of their hearts in open chest and on artificial respiration to noradrenaline and propranolol were studied. Values of the heart contractory function were by 32-140% higher in experimental animals than in control those. This excess could be eliminated by propranolol which shows it to be due to exaggerated effect of the adrenergic regulatory link. Adrenaline raises the heart function almost up to the maximal limit in adapted animals. This is followed by an increased rate of disappearance of the noradrenaline inotropic effect.