BUFFER CAPACITY IN THE BLOOD OF THE HEMOGLOBINLESS ANTARCTIC FISH CHIONODRACO-HAMATUS

Blood acid base homeostasis of the hemoglobinless Antarctic teleost Ch ionodraco hamatus was analyzed by measuring the titratable buffer capa city (beta) and carbonic anhydrase (CA) activity in blood samples. Res ults were compared with those obtained in the red-blooded temperate fi sh Anguilla anguilla. Data show that the titratable flood buffer capac ity of icefish, in the range of red-blooded teleost species, was signi ficantly higher than that of A. anguilla. Furthermore, plasma inorgani c phosphate and reactive sulfhydryl content was significantly higher i n the Antarctic species. No enzymatic activity of CA was detected in b lood samples of Antarctic fish, suggesting the absence of a blood CA-i sozyme. (C) 1997 Elsevier Science Inc.