1. Carbonic anhydrase activity in tissues of the icefish Chionodraco hamatus and of the red-blooded teleosts Trematomus bernacchii and Anguilla anguilla
- Author
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Mariella Rollo, Carlo Storelli, Michele Maffia, R Chiloiro, Antonia Rizzello, Raffaele Acierno, Maffia, Michele, Rizzello, Antonia, Acierno, Raffaele, M., Rollo, R., Chiloiro, Storelli, Carlo, Rizzello, A, Acierno, R, Rollo, M, and Chiloiro, R
- Subjects
Gills ,Gill ,Gene isoform ,animal structures ,Nothotheniodei ,Physiology ,carbonic anhydrase ,Antarctic Regions ,Antarctic teleost ,Trematomus bernacchii ,Aquatic Science ,Kidney ,Hemoglobins ,blood ,Chionodraco hamatus ,Carbonic anhydrase ,Trematomus ,medicine ,Animals ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,Carbonic Anhydrases ,Chaenichthyidae ,chemistry.chemical_classification ,Anguilla anguilla ,biology ,Fishes ,Carbonic anhydrase activity ,gill ,Anatomy ,Anguilla ,biology.organism_classification ,pH homeostasi ,Intestines ,medicine.anatomical_structure ,Enzyme ,Biochemistry ,chemistry ,haemoglobinle ,Chionodraco hamatu ,Insect Science ,biology.protein ,Animal Science and Zoology - Abstract
SUMMARY Carbonic anhydrase (CA) activity was measured in blood, intestine, kidney and gill of two Antarctic teleosts, the haemoglobinless Chionodraco hamatus and the red-blooded Trematomus bernacchii, and of the temperate teleost Anguilla anguilla. In all species, the highest CA activity was in the gills, with the greatest activity in C. hamatus. CA activity in the blood was highest in A. anguilla, but none was detected in the blood of C. hamatus despite the presence of plasma CA inhibitors. The enzyme was present but its activity was low in the intestine and kidney of all three species. The existence of very high CA activity in C. hamatus gills compared with the red-blooded species was investigated further by isolating and characterising the branchial cytosolic CA isoforms. The turnover rate of the C. hamatus isoform was significantly higher than that of T. bernacchii and A. anguilla. The isoforms from both the Antarctic species exhibited lower apparent Km (Km,app) and heat stability than those from A. anguilla. Sensitivity to sulphonamides was similar in all species and was within the range of the mammalian CA II isoform. The branchial CA isoforms of C. hamatus, T. bernacchii and A. anguilla displayed relative molecular masses of 28.9, 29.9 and 31.2 kDa, respectively. The results suggest that the hemoglobinless teleost possesses a different branchial cytosolic CA isoform from that of red-blooded teleosts.
- Published
- 2001