Absence of apparent cell pH variations during hypoxia in the carotid body chemoreceptors in vitro.

Abstract The intracellular pH in the carotid body and the superior cervical ganglion in vitro was measured under conditions of hyperoxia (100% O 2 ) and hypoxia (10% O 2 ) using 5,5-dimethyl-2,4-oxazolidinedione (DMO) and methylamine as pH indicators. No differences in intracellular pH values were found between hyperoxic and hypoxic carotid bodies. Thus, these data do not support the hypothesis that chemoreceptor excitation is mediated by a change in intracellular H + ion concentration.