Absence of pH changes during altered work in the in vivo sheep heart: a 31P-NMR investigation.

Abstract

Saturation transfer from gamma-ATP to inorganic phosphate was used to assign the intracellular inorganic phosphate resonance of the phosphorus-31 nuclear magnetic resonance spectrum of heart obtained from adult sheep under Halothane anesthesia. The 31P chemical shift of intracellular inorganic phosphate was then used as a probe of myocardial pH. Resting myocardial pH was found to be 7.03 +/- 0.02. The effects of increasing myocardial work on myocardial pH were examined using external pacing and phenylephrine infusion alone or in combination to produce steady-state increases in the rate-pressure product. No alteration in myocardial pH was observed with up to 4-fold increases in rate-pressure product. No changes in high-energy phosphates were observed except at the highest rate-pressure products obtained, where small increases in inorganic phosphate and decreases in the phosphocreatine/ATP ratio were observed. In addition, the transition to a new steady state was studied with a 20-s time resolution after initiation of pacing. Again, no changes in pH or levels of phosphates were detected during the transition to increased work.

Statistics

050100'93'96'99'02'05'08'11'14'17
Citations per Year

115 Citations

Semantic Scholar estimates that this publication has 115 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Detre1990AbsenceOP, title={Absence of pH changes during altered work in the in vivo sheep heart: a 31P-NMR investigation.}, author={John A. Detre and Alan P. Koretsky and Denise S. Williams and C Kiong Ho}, journal={Journal of molecular and cellular cardiology}, year={1990}, volume={22 5}, pages={543-53} }