Affiliation:
1. From the Departments of Medicine (J.Z., D.J.D., T.P., A.H.L.F., R.J.B.), Biochemistry (K.U.), and Radiology (K.U.) and the Center for Magnetic Resonance Research (J.Z., X.Y., Y.Z., H.W., H.M., K.U.), University of Minnesota Health Sciences Center and the Department of Veterans Affairs Medical Center (A.H.L.F.), Minneapolis.
Abstract
BackgroundThis study tested the hypothesis that31P nuclear magnetic resonance (NMR)–detectable 2-deoxyglucose (2DG) uptake is increased in chronically pressure-overloaded hypertrophied left ventricular myocardium.Methods and Results31P NMR spectroscopy was used to determine the transmural distribution of high-energy phosphate levels and 2-deoxyglucose-6-phosphate (2DGP) accumulation during intracoronary infusion of 2DG (15 μmol · kg body wt−1· min−1) in eight normal dogs and in eight dogs with severe left ventricular hypertrophy (LVH) produced by ascending aortic banding. The ratio of LV weight to body weight was 8.25±0.65 g/kg in the LVH group compared with 4.35±0.11 g/kg in the normal group (P<.01). Myocardial ATP content was decreased by ≈40% and phosphocreatine (PCr) by ≈60% in LVH hearts. ATP values were transmurally uniform in LVH and normal hearts, whereas PCr was lower in the subendocardium (Endo) than the subepicardium (Epi) of both groups. The PCr/ATP ratio was lower in LVH hearts (1.72±0.05, 1.64±0.07, and 1.53±0.10 in Epi, midwall, and Endo, respectively) compared with normal hearts (2.36±0.05, 2.09±0.06, and 1.96±0.06; eachP<.01 normal versus LVH). Arterial blood levels of glucose, insulin, and free fatty acids were comparable between groups, whereas arterial lactate and norepinephrine levels were significantly higher in the LVH group. 2DG infusion did not affect systemic hemodynamics or myocardial high-energy phosphate or inorganic phosphate levels in either group. At the end of 60 minutes of 2DG infusion, there was no detectable accumulation of 2DGP in the normal hearts. However, seven of the eight LVH hearts showed time-dependent accumulation of 2DGP, which was linearly related to the severity of hypertrophy (r=.90 for subendocardial 2DGP versus LV weight/body weight). A transmural gradient of 2DGP was present, with greatest accumulation in the subendocardium (3.3±1.6, 5.8±2.3, and 7.9±2.2 μmol/g in Epi, midwall, and Endo of the LVH hearts, respectively;P<.05 Epi versus Endo).ConclusionsThe pressure-overloaded hypertrophied left ventricle demonstrated increased accumulation of 2DGP detected with31P NMR spectroscopy. Accumulation of 2DGP was positively correlated with the degree of hypertrophy and was most marked in the subendocardium.
Publisher
Ovid Technologies (Wolters Kluwer Health)
Subject
Physiology (medical),Cardiology and Cardiovascular Medicine
Cited by
69 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献