Premium
In vitro carbon dioxide excretion from erythrocytes of two species of Antarctic fishes and its inhibition by catecholamines
Author(s) -
Powell M. D.,
Forster M. E.,
Davision W.
Publication year - 2000
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.2000.tb02248.x
Subject(s) - carbonic anhydrase , excretion , acetazolamide , biology , bohr effect , carbon dioxide , in vitro , biochemistry , medicine , endocrinology , hemoglobin , oxygen–haemoglobin dissociation curve , enzyme , ecology , physiology
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.