An experimental model was developed to evaluate the effects of activators and inhibitors of K(ATP) channels on unidirectional K+ fluxes in the whole heart. Isolated rat hearts perfused in the Langendorff mode were equilibrated with Pi-free Krebs-Henseleit buffer (KH buffer) containing 0.94-2.14 mM R
Simultaneous measurement of both lipid and lactate in isolated rat hearts by 1H NMR spectroscopy
✍ Scribed by Laura C. Stewart; John K. Saunders; Roxanne Deslauriers; Dominique Bourgeois; Jean-François J. Nédélec
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 576 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0740-3194
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✦ Synopsis
Abstract
Myocardial lipid and lactate levels are sensitive indicators of biochemical status: lipid levels have been shown to increase in response to high fat diets, disease or metabolic stress and elevated lactate levels are indicative of reduced oxygen supply. Selective measurement of lactate or lipid levels by ^1^H NMR is not straightforward since both the lactate methyl group and lipid methylene groups resonate at 1.3 ppm. We have overcome this difficulty by employing spectral editing techniques to observe both lipid methylene and lactate methyl resonances, and have measured lipid and lactate levels in perfused rat hearts during control perfusion and in response to metabolic stress. Lactate increased during ischemia and decreased during reperfusion, and the ischemia‐induced increase is inhibited by iodoacetate, as expected. In contrast, lipid levels increased during ischemia and remained elevated during reperfusion. Hearts from rats fed high fat diet show elevated lipid levels during control perfusion. Data obtained by ^1^H NMR are consistent with biochemical data, validating the technique.
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