Effect of adrenaline on the response of erythrocyte 2,3-diphosphoglycerate in rabbits in vivo.

1. A 6 hr time-course response of erythrocyte 2,3-diphosphoglycerate was studied in rabbits following adrenaline administration. 2. Eight female New Zealand white rabbits weighing about 3.6 Kg each were injected intra-peritoneally with a total of 0.97 mg/kg of adrenaline (0.56 mg/kg at time 0 min and 0.41 mg/kg at time 0.5 hr), and the venous level of red blood cell (RBC) 2,3-DPG was monitored at 0 hr, 1 hr, 3 hr, and 6 hr, respectively. As controls, the level of 2,3-DPG was also monitored in these rabbits weeks prior to the experiment. 3. A significant (p < 0.05) rise in the mean level of 2.3-DPG (mumol.ml-1 RBC) was reached 3 hr after the initial injection of adrenaline, and the level returned to the preexposure level by the end of 6 hr. 4. It is speculated that adrenaline may be one of the contributors that increases the level of 2,3-DPG during the resting period following exhaustive exercise because this catecholamine has been reported to increase following this type of hypoxia.