title: Urea tolerance as a molecular adaptation of elasmobranch hemoglobins.
abstract: 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.
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D002263:Carboxyhemoglobin / Q000378:metabolism; D004284:Dogfish; D004361:Drug Tolerance; D005399:Fishes / Q000097:blood*; D006454:Hemoglobins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010100:Oxygen / Q000097:blood; D010108:Oxyhemoglobins / Q000378:metabolism; D010313:Partial Pressure; D012623:Seawater; D012754:Sharks; D012965:Sodium Chloride / Q000494:pharmacology; D013268:Stimulation, Chemical; D014508:Urea / Q000097:blood* / Q000494:pharmacology
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; D012965:Sodium Chloride; D014508:Urea; D002263:Carboxyhemoglobin; D010100:Oxygen