HILL, E.M.; WICKLER, S.J.*; SZEWCZAK, J.M.; GREENE, H.M.; COGGER, E.A.: 2,3-diphosphoglycerate in burros (Equus asinus) after six weeks at altitude
Research from our laboratory indicates that both horses and mules increase concentrations of 2,3-DPG in their red cells after acclimatization to high altitude. This increase has been argued to aid in the acclimatization process by facilitating oxygen unloading in the tissues. We were unable to find values for burros, so this study was undertaken to add to our baseline data on equids at altitude. Twelve burros on pasture at 1220 m for one year and 12 other burros that had been at elevation for six weeks (3000-3400 m) were sampled. The high-altitude acclimated burros were sampled approximately 4 hrs after arrival at 1220m. Venous blood samples were collected and immediately pipetted into ice cold TCA. DPG was analyzed spectrophotometrically. In order to reduce errors produce by differences in packed cell volume, DPG values are expressed per packed cell volume. Mean differences were analyzed using an unpaired student’s t-test. Six weeks at altitude did not produce any increase in packed cell DPG (p=0.49, means ± 1 SE): 6.33 ± 0.36 �moles/ml for low altitude burros vs. 6.01± 0.30 µ moles/ml for high altitude burros. The concentrations are similar to those of horses and mules from low altitude. It is unlikely that DPG in the high altitude animals decreased in the short time they were at 1220 m prior to sampling; The DPG concentrations in mules and horses were elevated 100 and 32%, respectively, using a similar study paradigm. In a more tightly controlled study, DPG concentrations in horses were still elevated 48 hours after a 10-day sojourn to 3800 m. Supported by Three-Corner Round Pack Outfit and grants from the Center for Equine Health (UC Davis) and an Agricultural Research Initiative.
