Evolutionary determinants of normal arterial plasma pH in ectothermic vertebrates

Burton, R. F. (2002) Evolutionary determinants of normal arterial plasma pH in ectothermic vertebrates. Journal of Experimental Biology, 205(5), pp. 641-650. (PMID:11907053)

Full text not currently available from Enlighten.

Publisher's URL: http://jeb.biologists.org/content/205/5/641


Mean values of normal arterial pH in different species of fish, amphibians and reptiles at 15 and 25 degrees C, taken from the literature, are negatively correlated with arterial P(CO(2)) and plasma [Na(+)]. At either temperature, the data accord with the hypothesis that extracellular acid-base homeostasis evolved to maintain an optimal pH at particular cell-surface sites that are similar in all species. These hypothetical sites bear fixed negative charges that attract H(+), but which are partially screened by Na(+); for the surface pH to be constant, the bulk interstitial pH should then vary inversely with [Na(+)], as is the case. At the same time, the bulk interstitial fluid must be more acid than arterial plasma by an amount that increases with decreasing arterial P(CO(2)). With allowance made for additional screening by Ca(2+) and Mg(2+), the relevant cell-surface pH is probably approximately 6.2.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Burton, Dr Richard
Authors: Burton, R. F.
College/School:College of Medical Veterinary and Life Sciences > School of Life Sciences
Journal Name:Journal of Experimental Biology
Publisher:Company of Biologists
ISSN (Online):1477-9145
Published Online:01 March 2002

University Staff: Request a correction | Enlighten Editors: Update this record