Biophysical Journal 50: 837-841 (1986)
© 1986 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Curtin, N A Search for Related Content PubMed PubMed Citation Articles by Curtin, N A

Buffer power and intracellular pH of frog sartorius muscle.

ABSTRACT

Intracellular pH (pHi) and buffer power of frog muscle were measured using pH-sensitive microelectrodes under conditions used previously in energy balance experiments because pH strongly influences the molar enthalpy change for phosphocreatine splitting, the major net reaction during brief contractions. The extracellular pH (pHe) of HEPES buffered Ringer's solution influenced pHi, but change in pHi developed slowly. Addition or removal of CO2 or NH3 from the extracellular solution caused a rapid change in pHi. The mean buffer power measured with CO2 was 38.4 mmol.l-1.pH unit-1 (+/- SEM 2.1, n = 49) and with NH3 was 36.2 (+/- SEM 5.5, n = 4) at 20-22 degrees C. At 5 degrees C, in experiments with CO2 the mean buffer power was 40.3 (+/- SEM 2.6, n = 3). For pHi values above approximately 7.0, the observed buffer power was greater than that expected from the values in the literature for the histidine content of intracellular proteins, carnosine and inorganic phosphate in the sarcoplasm. The measured pHi values were similar to those assumed in energy balance calculations, but the high measured buffer power suggests that other buffering reactions occur in addition to those included in energy balance calculations.

This article has been cited by other articles:

				J. A. Usher-Smith, J. A. Fraser, P. S. J. Bailey, J. L. Griffin, and C. L.-H. Huang The influence of intracellular lactate and H+ on cell volume in amphibian skeletal muscle J. Physiol., June 15, 2006; 573(3): 799 - 818. [Abstract] [Full Text] [PDF]

				A. Vezzoli, M. Gussoni, F. Greco, and L. Zetta Effects of temperature and extracellular pH on metabolites: kinetics of anaerobic metabolism in resting muscle by 31P- and 1H-NMR spectroscopy J. Exp. Biol., September 1, 2003; 206(17): 3043 - 3052. [Abstract] [Full Text] [PDF]