In vivo and in vitro CO 2 titration curves in the rabbit: Adaptation to hypercapnic conditions

Abstract

1. 1. Arterial blood acid-base status of unanesthetized, unrestrained rabbits was studied during 6–12 hr of exposure to 7, 10 and 14.5% CO 2. 2. 2. Most of the changes in blood acid-base status occurred during the first 20–60 min of exposure to hypercapnia and only minor changes occurred during the remaining exposure period (up to 12 hr). 3. 3. Blood buffer values obtained were not different from those reported for other terrestrial mammals. 4. 4. The whole body buffer values obtained here for the rabbit (0.58 nM H +mmHg P CO 2 is higher than that reported previously for man and dog. This relatively high whole body buffer value complies well with the high tolerance to CO 2 reported for the rabbit.