End-systolic pressure-volume and MV̇O2-pressure-volume area relations of isolated rat hearts

T. Wannenburg, S. P. Schulman, D. Burkhoff

Research output: Contribution to journalArticlepeer-review

Abstract

We tested the utility of a standard isolated, crystalloid-perfused, isovolumic rat heart preparation for studying ventricular metabolism in terms of the myocardial oxygen consumption-pressure-volume area (MV̇O2-PVA) relations. The end-systolic pressure-volume relations (ESPVRs) determined between volumes of 0.15 and 0.65 ml were fit equally well by linear and nonlinear regression analysis within the data range but predicted widely differing volume-intercept (V(o)) values. Linear regression analysis of the ESPVRs provided a mean slope (E(es)) of 419 ± 186 mmHg·g·ml-1 and V(o) of 0 ± 0.12 ml, respectively (n = 6). The MV̇O2-PVA relations were linear with a slope and MV̇O2 intercept of 1.30 ± 0.31 x 10-5 ml O2·mmHg- 1·ml-1 and 0.38 ± 0.09 x 10-3 ml O2·beat-1·g-1, respectively. These MV̇O2-PVA parameters were not significantly different from those obtained when nonlinear regression analysis was applied to the ESPVR. Decreasing perfusate calcium concentration ([Ca2+]) (n = 7) resulted in a downward shift in the ESPVR, a decrease in the MV̇O2-PVA intercept (0.52 ± 0.26 vs. 0.34 ± 0.20 x 10-3 ml O2·beat-1·g-1, P < 0.01), and no significant change in the MV̇O2-PVA slope (1.33 ± 0.47 vs. 1.57 ± 0.69 x 10-5 ml O2·mmHg-1·ml-1, NS). We conclude that this preparation may be a useful alternative to more expensive preparations for selected experiments in cardiac energetics.

Original languageEnglish (US)
Pages (from-to)H1287-H1293
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume262
Issue number4 31-4
DOIs
StatePublished - 1992

Keywords

  • calcium
  • cardiac energetics
  • contractility

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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