EFFECTS OF HYPOXIA AND HYPEROXIA ON OXYGEN-TRANSFER PROPERTIES OF THEBLOOD OF A VIVIPAROUS SNAKE

Red cell oxygen affinity, red cell nucleoside triphosphate (NTP) level s and blood oxygen-carrying capacity were determined for male, nonpreg nant and pregnant female, and fetal garter snakes Thamnophis elegans e xposed to hypoxia (5 % oxygen) and hyperoxia (100 % oxygen), Male and nonpregnant female snakes were maintained under these conditions for u p to 3 weeks and exhibited an apparent maximal change in oxygen affini ty after 14 days of hypoxia and hyperoxia, Red cell NTP levels decreas ed and oxygen affinity increased with exposure to hypoxia, while expos ure to hyperoxia promoted an increase in red cell NTP concentrations a nd a decrease in red cell oxygen affinity in the males, Hyperoxia-expo sed nonpregnant females did not show a significant change in oxygen af finity, After 14 days of hypoxia, the pregnant females showed an incre ase in red cell oxygen affinity which was associated with a decrease i n red cell NTP concentration and in the molar ratio of NTP/hemoglobin relative to normoxic controls, Fourteen days of hyperoxia did not resu lt in a change in oxygen affinity of red cells from the pregnant femal e, but did promote a slight increase red cell NTP concentrations. The blood parameters of fetuses from females exposed to hypoxia or hyperox ia did not differ from those of normoxic control fetuses. The fetuses of females exposed to hypoxia suffered greater mortality, appeared les s developed and had a lower average wet mass than the fetuses of normo xic- and hyperoxic-exposed females. Neither hypoxia nor hyperoxia alte red the oxygen-carrying capacity of the blood in any group of snake.