Beta-adrenergic receptors and oxygen transport.

We investigated whether stimulation of baboon erythrocyte beta-adrenoreceptors affects oxygen transport by haemoglobin. To assess oxygen transport we measured the PO2 at which the haemoglobin was 50% saturated (P50) and the Hill parameter 'n'. Blood at PO2s ranging from 10 to 90 mm Hg was exposed to a 10(-3) M concentration of the agonists l-isoproterenol, l-epinephrine and l-norepinephrine in the presence and absence of 10(-5) M dl-propranolol. None of the adrenergic agents which were used in these experiments produced significant changes in either 'n' or P50 and the concentrations of 2,3-diphosphoglycerate and lactate were not altered by the agonists. We conclude from these results that short-term adrenergic stimulation of the baboon erythrocyte beta-adrenoreceptor does not affect factors known to influence oxygen transport, oxygen delivery or haemoglobin itself.