Journal
RESPIRATION PHYSIOLOGY
Volume 128, Issue 3, Pages 317-329Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/S0034-5687(01)00309-7
Keywords
erythrocyte; hypoxic response; cell volume; evolution; hypoxia; haemoglobins; fish; teleost; hypoxia; erythrocytic response; vertebrates; vertebrates; agnathans; terrestrial; volume; cell; hypoxia
Categories
Ask authors/readers for more resources
The evolution of erythrocytic hypoxia responses is reviewed by comparing the cellular control of haemoglobin-oxygen affinity in agnathans, teleost fish and terrestrial vertebrates. The most ancient response to hypoxic conditions appears to be an increase in cell volume, which increases the haemoglobin-oxygen affinity in lampreys. In teleost fish, an increase of cell volume in hypoxic conditions is also evident. The volume increase is coupled to an increase in erythrocyte pH. These changes are caused by an adrenergic activation of sodium/proton exchange across the erythrocyte membrane. The mechanism is important in acute hypoxia and is followed by a decrease in cellular adenosine triphosphate (ATP) and guanosine triphosphate (GTP) concentrations in continued hypoxia. In hypoxic, bird embryos, the ATP levels are also reduced. The mechanisms by which hypoxia decreases cellular ATP and GTP concentrations remains unknown, although at least in bird embryos cAMP-dependent mechanisms have been implicated. In mammals, hypoxia responses appear to occur mainly via modulation of cellular organic phosphate concentrations. In moderate hypoxia, 2,3-diphosphoglycerate levels are increased as a result of alkalosis caused by increased ventilation. (C) 2001 Elsevier Science B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available