What question did this study set out to answer?

To evaluate whether the oxidation and clearance kinetics of radiolabeled acetate reliably reflect myocardial tricarboxylic acid cycle activity under varying workloads and substrate conditions.

September 1, 1988Circulation ResearchOpen Access

Radiolabeled acetate as a tracer of myocardial tricarboxylic acid cycle flux.

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Authors

DBDenis B. BuxtonNational Institutes of Health MSMarkus SchwaigerUniversity of Pisa ANAnh Minh NguyenNortheastern University

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Implication

Laboratory study demonstrates that radiolabeled acetate clearance correlates strongly with tricarboxylic acid cycle flux in isolated rat hearts, suggesting its utility as a metabolic tracer.

Key Points

To evaluate whether the oxidation and clearance kinetics of radiolabeled acetate reliably reflect myocardial tricarboxylic acid cycle activity under varying workloads and substrate conditions.
Administered bolus injections of [1-14C]acetate into isolated perfused rat hearts under normoxia, hypoxia, and phenylephrine stimulation.
Assessed clearance kinetics of effluent 14CO2 and total 14C across fourfold variations in myocardial oxygen consumption and in the presence of competing substrates (lactate, DL-3-hydroxybutyrate, and palmitate).
The clearance rate constant of 14CO2 correlated strongly with tricarboxylic acid cycle flux estimated from oxygen consumption (r = 0.93), with clearance half-times shifting from 3.1 ± 0.5 minutes at baseline to 2.2 ± 0.2 minutes with phenylephrine and 7.2 ± 1.2 minutes during hypoxia.
Alternate substrates did not affect [1-14C]acetate clearance kinetics, whereas 2 mM lactate prolonged the clearance half-time of [1-14C]palmitate from 3.0 ± 0.4 minutes to 4.3 ± 0.2 minutes (n = 3, p < 0.01).
Effluent 14CO2 represented 88% to 98% of total effluent 14C between 10 and 20 minutes following bolus injection, confirming that 14C clearance directly reflects acetate oxidation.

Cite This Study

Buxton et al. (1988) studied this question.

synapsesocial.com/papers/6a99d114819ffb2fe2b4eb25 https://doi.org/10.1161/01.res.63.3.628

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Implication

Laboratory study demonstrates that radiolabeled acetate clearance correlates strongly with tricarboxylic acid cycle flux in isolated rat hearts, suggesting its utility as a metabolic tracer.

Radiolabeled acetate as a tracer of myocardial tricarboxylic acid cycle flux.

Discussion

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Implication

Key Points

Cite This Study

Radiolabeled acetate as a tracer of myocardial tricarboxylic acid cycle flux.

Discussion

Member takes

Implication

Key Points

Cite This Study

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