CSF ION COMPOSITION AND MANIPULATION DURING THERMOREGULATION IN AN AVIAN SPECIES, GALLUS-DOMESTICUS

1. 1. At thermoneutrality (28°C), CSF Na+: Ca2+ in hens was 61.66; under thermal stress (39°C), it changed to 59.38 (30 min), 62.58 (3 hr), and 52.44 (10 hr); no change in ratio occurred at 15°C. 2. 2. ICV Ouabain and/or EGTA increased body temperature (TR) but not respiration rate (RR) at 39°C. 3. 3. A 28°C, Ouabain decreased, and EGTA increased, TR and RR. 4. 4. Ca2+ may be more critical than Na+ in thermoregulation. 5. 5. Heat stress appears to stimulate Na+-transport mechanisms other than Na+-ATPase. 6. 6. RR apppears to be a function of TR, not of ion balance. © 1990.