Intracellular buffering power

Range Table - link mmol/pH/Liter
Organism Metazoa animals
Reference Roos A, Boron WF (1981) Intracellular pH. Physiol Rev 61: 296–434 p.399 table 13PubMed ID7012859
Primary Source See pointers to refs on right of table
Method "Table 13 summarizes the available data on intracellular buffering power. The values obtained by titrating cell homogenates ideally reflect physicochemical buffering but may also reflect a degree of metabolic and organellar buffering and some contamination from metabolic breakdown of the sample. In some instances, extracellular contributions were not taken into account. The remainder of the values were obtained by titrating intracellular fluid in situ, either by exposing cells to weak acids and bases or by microinjection techniques. The ?pHi measurements for these in situ data were all obtained with microelectrodes. In some cases acid extrusion occurring after acute intracellular acid loads may not have been totally compensated for. Experiments were usually performed at an approximately normal pHo, so that passive fluxes of acid or base are unlikely to have had a substantial effect." See methods on 3rd column from left
Comments "A considerable number of estimates of buffering power, many from in vivo mammals, are omitted from Table 13 because they are likely to have been heavily contaminated by active or passive transmembrane fluxes of acid or base. The value of ß [buffering power] has long been estimated by changing PCO2 and then measuring the resultant fall of pHi several hours later." See notes beneath table
Entered by Uri M
ID 110775