Circulating Red Cells in Rats with Similar Tissue PO2 but Differing PCO2.
Final rept. Jan 71-Dec 72,
SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TEX
Pagination or Media Count:
To investigate the effect of CO2 upon erythropoiesis, adult female rats were exposed to 1 of 3 gaseous environments designed to produce similar tissue PO2, but widely differing PCO2. Tissue PCO2 was varied from 38 to 69 torr, while PO2 averaged near 22 torr. Inspired PO2 of the nonhypercapnic rats approximated that found at 11,000-ft. altitude. Tissue PO2 and PCO2 were estimated from measurements of subcutaneous-gas-pocket contents. Hematocrit and circulating red cell volume were significantly P .001 greater in two hypercapnic groups as compared with those inspiring no CO2 after 40 days of continuous exposure. Reticulocyte counts were greater in two hypercapnic groups after four days of exposure P .001, but not after 40 days. The conclusion is that when tissue PO2 was held constant, additional CO2 increased the circulating red cells.
- Stress Physiology