The effect of peripheral chemodenervation on the ventilatory response to potassium

Abstract

The present experiments were designed to test the hypothesis that the increase in plasma potassium which occurs during exercise acts as a stimulus to respiration via the peripheral chemoreceptors. The effect of intravenous infusion of KCl on ventilation was measured in anaesthetised cats while they were loaded with CO2 intravenously via a bubble gas exchanger. Ventilation during K+ infusion was compared with that immediately before in 'intact' and peripherally chemodenervated cats. In the 'intact' group there was a highly significant increase in ventilation of approximately 25% (+253 +/- 22 ml/min, P less than 0.001), whereas in the chemodenervated group there was no significant change (+ 17 +/- 11 ml/min) in spite of similar increases in arterial K+ concentration. The results of these experiments indicate that K+ infusions stimulate ventilation and that this effect is abolished by peripheral chemodenervation.