Urea Tolerance as a Molecular Adaptation of Elasmobranch Hemoglobins

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Science  04 Oct 1974:
Vol. 186, Issue 4158, pp. 57-59
DOI: 10.1126/science.186.4158.57


Urea is maintained at moderately high concentrations in the blood and tissues of marine elasmobranchs. Functional properties of the hemoglobins fromn several elasmobranch species are unaffected by urea concentrations as high as 5 molar. This in. sensitivity to urea, which is not observed with human hemoglobin, is accompanied by an increased sensitivity to sodium chloride.