Journal article
Use of 2,3-butanedione monoxime to estimate nonmechanical VO2 in rabbit hearts
The American journal of physiology, Vol.265(3 Pt 2), pp.H834-H842
09/1993
Handle:
https://hdl.handle.net/2376/115103
PMID: 8214117
Abstract
The purpose of the present study was to evaluate the feasibility of partitioning myocardial O2 consumption (VO2) into mechanical and nonmechanical components in the whole heart preparation using a negative inotrope, 2,3-butanedione monoxime (BDM), which has been reported to have a selective effect on the contractile proteins in a low concentration range (< 6 mM). In six isolated bovine red blood cell-perfused rabbit hearts, VO2 and force-time integral (FTI) were measured during infusion of varying concentrations of BDM at a constant left ventricular volume chosen such that control left ventricular peak isovolumic pressure was approximately 100 mmHg. The VO2-FTI relation with BDM concentrations < or = 5 mM was highly linear (median r = 0.98). Its VO2-axis intercept at zero FTI had a positive value (mean 23% of control, 0.014 ml O2.beat-1 x 100 g-1). To confirm the selective effect of BDM on the contractile proteins, the intracellular free Ca2+ transient was measured with the fluorescent indicator indo 1 in three isolated buffer-perfused rabbit hearts. The amplitude of the Ca2+ transient was not altered by BDM at concentrations < or = 10 mM, although left ventricular developed pressure was markedly depressed. This finding indicates that BDM < or = 10 mM does not affect excitation-contraction coupling. We conclude that the VO2-axis intercept value of the VO2-FTI relation during BDM infusion in a low concentration range represents VO2 for nonmechanical energy utilization. The BDM method to partition VO2 into mechanical and nonmechanical components is thus feasible in the whole rabbit heart.
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Details
- Title
- Use of 2,3-butanedione monoxime to estimate nonmechanical VO2 in rabbit hearts
- Creators
- H Yaku - Cardiology Unit, College of Medicine, University of Vermont, Burlington 05405B K SlinkerT MochizukiB H LorellM M LeWinter
- Publication Details
- The American journal of physiology, Vol.265(3 Pt 2), pp.H834-H842
- Academic Unit
- Integrative Physiology and Neuroscience, Department of
- Publisher
- United States
- Grant note
- HL-45116 / NHLBI NIH HHS HL-28939 / NHLBI NIH HHS
- Identifiers
- 99900548141001842
- Language
- English
- Resource Type
- Journal article