This study examined the effect of temperature on hemolymph and intracellular acid-base status in the locust, Schistocerca nitens. Hemolymph pH decreased with temperature by 0.017 pH units·°C-1 above 25°C, but was stable at lower temperatures. Average intracellular pH (pHi, calculated from CO2 distribution) decreased by approximately 0.018 pH units·°C-1, in accordance with predictions for preservation of relative alkalinity and protein charge state. DMO was found to be unsuitable for use as an in vivo pHi marker in locusts due to rapid metabolism and excretion of this compound. Hemolymph pH regulation when temperature changed was accomplished by a combination of variation of PCO2 and [HCO3-], with changes in [HCO3-] predominating. Digestive tracts contained a large portion of total body water (over 30%), and total body CO2 (over 40%). Variation in [HCO3-] may dominate pH regulation in locusts because of the relatively large size of the digestive tract and its powerful acid-base transporting capacities.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Animal Science and Zoology