Respiratory response to HCl acidosis in dogs after carotid body denervation

Abstract

To test the carotid body participation in the respiratory response to metabolic acidosis, dogs (6) were infused with HCl for 2 h followed by HCl feeding to prolong the acidosis to 48 h. This protocol was repeated after carotid body denervation (CBD). Mean control PCO2 [partial pressure of CO2] rose by 7.3 Torr after CBD. PCO2 fell comparably during acidosis before and after CBD at all time periods from 30-48 h and returned to control levels by 72 h. The pH ranged from 7.10-7.30 during acidosis pre- and post-CBD. The decreases in pH and HCO3- concentration did not differ significantly at any time interval between the pre- and post-CBD studies. In dogs, moderately severe HCl acidosis apparently stimulated ventilation acutely and chronically through a central mechanism in the absence of the carotid bodies.