The effect of beta adrenergic blockade on the carotid body response to hyperkalaemia in the cat.

摘要: Arterial chemoreceptor discharge and ventilation are both significantly increased when the concentration of arterial potassium is raised to a level typical moderate exercise. However, although plasma exercising, beta-blocked patients rises by more than that normal subjects, this does not show up in their steady-state ventilatory response, i.e. exercising subjects ventilate no controls. The present experiments were designed test hypothesis apparent failure respond extra hyperkalaemia they experience might be accounted for reduction sensitivity chemoreceptors potassium. We used eleven pentobarbitone-anaesthetized, thoracotomized, artificially hyperventilated cats, which was from ca. 4.5 7 mM before during beta blockade propranolol or atenolol. relation between curvilinear, becoming sensitive as latter raised. Beta reduced at all levels (P less 0.0001). It also 0.05) slope response given increase Our results decreases increases This may explain why breathe harder controls, spite fact hyperkalaemic.