ISSN:
1435-1803
Keywords:
Stable isotopes
;
mass spectrometry
;
working rat heart
;
metabolism
;
acetate
;
palmitate
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The technique described in this communication enables detailed investigations of cardiac metabolism using13C-labeled substrates and mass spectrometric measurements of13CO2 in the coronary effluent. To validate this technique for further studies isolated working rat hearts were perfused with13C-labeled substrates in a bicarbonate-free perfusion fluid. The fraction of CO2 produced by oxidation of labeled substrate was calculated by the13CO2/CO2 ratio in the coronary perfusate. The oxidation of13C-acetate showed a linear correlation with13C-acetate concentrations between 0.015 and 0.16 mmol/l. An inhibitor of acylcarnitine translocase, 2-(3-methylcinnamylhydrazono)-propionate (BM42.304) decreased CO2 production from13C-palmitate from 48%±4% to 31%±3% (n=11, SEM). Taking into account considerations of tracer kinetic theory rapidly accessible intracellular palmitate stores were estimated to be less than 900 nmol/g ww. This technique allows specific investigations of the oxidation of labeled substrates in the heart and may be useful for basic research and/or clinical diagnosis, thus avoiding the hazards of radiolabeled substrates.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00794999
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