³¹P and ¹H magnetic resonance spectroscopy of acute alcohol cardiac depression in rats

Abstract

Cardiac depression in the isolated rat heart perfused with 4% ethanol was correlated with intracellular phosphate energetics and tissue water distributions. Energy metabolites were assessed using 31P magnetic resonance spectroscopy (MRS) and correlated to the mitochondrial redox state using epicardial surface fluorometry. Changes in myocardial water compartmentation were measured by using 1H NMR spectroscopy with an extracellular chemical-shift reagent (DyTTHA) and correlated to results of 2D echocardiography (2DE). During alcohol perfusion there was a significant decrease in developed pressure and in coronary flow. No change was seen in ATP, PCr, pHi, Pi, or NADH. After withdrawal of alcohol from the perfusate cardiac function reverted to control values without a depletion of energy levels. During alcohol perfusion 1H MRS showed a marked redistribution of water from the intra- to the extracellular space, corresponding to a 35% left ventricular wall thinning confirmed by 2DE. The results indicate that acute alcohol cardiac depression is related to a dehydration of myocardial cells, but is not associated with intracellular acidosis or energy depletion.

Influence of Hypoxia and Hyperoxia on the Cardiovascular and Lethal Effects of Ethanol

“…It is generally agreed that ethanol has a dose-dependent myocardial depressive activity, as demonstrated in isolated heart preparations (Sulzer 1924;Wakim 1946 Nakano & Kessinger 1972;Friedman et al 1979;Strubelt 1980;Auffermann et al 1988;Bruyere & Stith 1994) and in man (Ahmed et al 1973;Timmis et al 1974;Kuhn et al 1976). Reduced myofilament response to calcium seems to be the reason for the contractile depression at clinically relevant ethanol concentrations (Danziger et a/.…”

Glycolysis in heart failure: a31P-NMR and surface fluorometry study

“…No adjustment was made for bound PCr and ATP (1,2,3). In earlier studies this correction was made (31, 41), however, ratios obtained from P-31 NMR correlated better with HPLC values if no correction for bound PCr and ATP was made (1,2,3).…”

“…The redox state was continuously monitored during the 90 s of global ischemia. The redox state reached maximum change in 45-60 s following onset of global ischemia, as described earlier (2). For assessing energy change the heart was freeze-clamped within 5 ms (39) at the end of the 90 s of ischemia.…”

Reversibility of chronic alcohol cardiac depression: 31P magnetic resonance spectroscopy in hamsters

“…Different from reperfusion after ischemia (25), there is no depletion of high-energy phosphate compounds after withdrawal of alcohol either in vitro (26,27) or in vivo (Fig. 4).…”

“…Cardiac dysfunction following chronic alcohol feeding was similar to other cardiomyopathies (16). However, in contrast to reequilibration of the heart after hypoxia (25) or anoxia (29), but similar to acute in vitro alcohol exposure (26,27), myocardial perfusion pressure for (A) control hamsters (heart dry weight, 108 f 8 pg), (B) hamsters fed with 50% alcohol for 3f months (heart dry weight, 85 +-8 pg), and (C) hamsters withdrawn from alcohol for 48 h after 50% alcohol feeding for 34 months (heart dry weight, 92 f 19 pg). The spectra are derived from one single animal in each group.…”