Red‐cell pH in tench. Interacting effects of cellular nucleoside triphosphates, Hb‐oxygenation and extracellular pH

Publisher Website
Google Scholar
Abstract
Experimental adjustments of red‐cell pH (pHi) by varying red‐cell nucleoside triphosphate (NTP) content, blood oxygenation state and extracellular pH (pHe) demonstrated a tight interdependence of these variables in their influence upon pHi The increase in pHi with deoxygenation (ΔpHi (d – o)) is large, but becomes strongly reduced when the NTP content is decreased and when pHe falls. Lowering of red‐cell NTP increases pHe, notably at high pHe but this NTP dependence of pHi (ΔpHi/A(NTP/Hb)) is much smaller in deoxygenated than in oxygenated blood. The pHi dependence of pHi (ΔpHi/ΔpHe) increases upon reduction of red‐cell NTP content and upon deoxygenation. The results are consistent with the view that pHi is governed by Donnan‐like distribution of protons across the red‐cell membrane, and show that a pronounced red‐cell swelling accompanies increases in the distribution ratio [H+]e/[H+]i. The data are interpreted in terms of changes in the red‐cell non‐permeable charge as induced by NTP and its linkage with the haemoglobin proton equilibria.