Effects of exercise and adrenaline on equine erythrocyte ATP content

To investigate the claim that equine erythrocytes released from the spleen are older cells than those found at rest in the circulation, the 2,3, diphosphoglycerate (2,3 DPG), adenosine triphosphate (ATP) and creatine concentration of erythrocytes before and following splenic emptying were examined. Normal values for thoroughbreds (43) and ponies (10) at rest were established. Following either exercise or intravenous injection of adrenaline in six thoroughbreds, there was an increase in erythrocyte creatine content and a decrease in ATP concentration. Exercise produced a slight increase in 2,3 DPG while no change occurred with adrenaline. In two splenectomised ponies adrenaline only produced a decrease in erythrocyte ATP, with no change in creatine or 2,3 DPG content. It was concluded that erythrocytes released from the spleen are not aged cells. However, the stimuli used produced a decrease in ATP content which may affect the properties of the erythrocytes.