... for adult fish but in accordance with embryonic pH i of a few non-fish species shortly after fertilization. Also, interstitial pH (pH int ) was significantly higher (8.08±0.25) than values for extracellular pH in adult fish. Distributions of HCO 3 - across membranes and between interstitium and ambient...

... 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...