In vitro carbon dioxide excretion from erythrocytes of two species of Antarctic fishes and its inhibition by catecholamines

• Published in: Journal of Fish Biology
• Main Authors: Powell, M. D., Forster, M. E., Davision, W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2000
• Subjects: Antarctic; Antarc*
• Online Access: http://dx.doi.org/10.1111/j.1095-8649.2000.tb02248.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1095-8649.2000.tb02248.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1095-8649.2000.tb02248.x

This study was designed to investigate whether the blood of Pagothenia borchgrevinki , exhibits a Haldane effect, and whether activation of a Na + /H + antiporter increases transport of intracellular protons and Bohr protons out of the erythrocytes resulting in inhibition of CO 2 excretion in both P. borchgrevinki , and Dissostichus mawsoni. When carbon dioxide dissociation curves were determined from blood samples pooled from three fish under oxygenated and deoxygenated conditions a Haldane effect was observed. Using an in vitro , CO 2 excretion assay, the rate of HCO 3 − dehydration was determined on blood and plasma equilibrated under an N 2 atmosphere then rapidly oxygenated with air in the presence of 10 −5 M noradrenaline or acetazolamide (10 04 M). Whole blood and plasma from P. borchgrevinki , and D. mawsoni , were equilibrated with 0·5% CO 2 in air and assayed in the presence of 10 −5 M noradrenaline. Erythrocyte CO 2 excretion rates were depressed significantly by noradrenaline in both species. The whole blood HCO 3 − dehydration rate was depressed significantly following rapid oxygenation in the presence of acetazolamide indicating that the pathway of CO 2 excretion included activation of intracellular carbonic anhydrase and an adrenergic receptor.