Effect of carbon monoxide exposures on erythrocytic 2,3-DPG in rabbits

To determine if an exposure to lower levels of carbon monoxide (CO) produces quantitative changes in erythrocytic 2,3-diphosphoglycerate (2,3-DPG), eight rabbits were exposed to 100 ppm CO for 5 h resulting in approximately 20% carboxyhemoglobin (HbCO). 2,3-DPG was determined before exposure and immediately after exposure as well as every 3 h during the 24 h following exposure. To determine if intermittent CO exposures over a prolonged period of time affect 2,3-DPG, an additional 12 rabbits were exposed to 250 ppm CO for three intermittent periods totaling 300 min daily for 14 days (30% HbCO). 2,3-DPG was determined once per animal at the end of each day's exposure period. All animals served as their own controls in both experiments. Neither the results of the 24-h time course nor those of the 14-day time course showed significant differences in mean 2,3-DPG between controls and exposed animals at any sampling time. Apparently erythrocytic 2,3-DPG plays neither a compensating nor aggravating role in respect to the hypoxia induced by these levels of HbCO in the rabbit.