Interactions between the hydrogen ion concentration and vasoconstrictor responses to catecholamines and sympathetic nerve stimulation.

Abstract

Vasoconstrictor responses to noradrenaline and adrenaline are reduced in acidemia. Vasoconstrictor responses to sympathetic nerve stimulation are reduced to a lesser extent than are initially equivalent responses to noradrenaline. Acidaemia increases adrenergic transmitter efflux and decreases neuronal uptake of noradrenaline. Infusions of catecholamines and sympathetic nerve stimulation induce acidaemia. The acidaemic effect of noradrenaline is mediated through actions on α-adrenoreceptors; that of isoprenaline is through β-adrenoreceptors; that of adrenaline involves both types of adrenoreceptors. The acidaemia induced by infusions of noradrenaline is largely responsible for the loss of th..