Effect of baroreceptor activity on ventilatory response to chemo- receptor stimulation

1975.-This study tested the hypothesis that ventilatory responses to chemoreceptor stimulation are affected by the level of arterial pressure and degree of baroreceptor activation. Carotid chemo-receptors were stimulated by injection of nicotine into the common carotid artery of anesthetized dogs. Arterial pressure was reduced by bleeding the animals and raised by transient occlusion of the abdominal aorta. The results indicate that ventilatory responses to chemoreceptor stimulation were augmented by hypotension and depressed by hypertension. In additional studies we excluded the possibility that the findings were produced by a direct effect of changes in arterial pressure on chemoreceptors. Both carotid bifurcations were perfused at constant flow. In one carotid bifur-cation, perfusion pressure was raised to stimulate carotid sinus baroreceptors. In the other carotid bifurcation, pressure was con-stant and nicotine was injected to stimulate carotid chemore