Nebivolol Prevents Up-Regulation of Nox2/NADPH Oxidase and Lipoperoxidation in the Early Stages of Ethanol-Induced Cardiac Toxicity

Changes in redox state are described in the early stages of ethanol-induced cardiac toxicity. Here, we evaluated whether nebivolol would abrogate ethanol-induced redox imbalance in the heart. Male Wistar rats were treated with a solution of ethanol (20% v/v) for 3 weeks. Treatment with nebivolol (10 mg/kg/day; p.o. gavage) prevented the increase of both superoxide (O2•-) and thiobarbituric acid reactive substances (TBARS) in the left ventricle of rats chronically treated with ethanol. Neither ethanol nor nebivolol affected the expression of Nox4, p47phox, or Rac-1. Nebivolol prevented ethanol-induced increase of Nox2 expression in the left ventricle. Superoxide dismutase (SOD) activity as well as the concentration of reduced glutathione (GSH) was not altered by ethanol or nebivolol. Augmented catalase activity was detected in the left ventricle of both ethanol- and nebivolol-treated rats. Treatment with nebivolol, but not ethanol increased eNOS expression in the left ventricle. No changes in the activity of matrix metalloproteinase (MMP)2 or in the expressions of MMP2, MMP9, and tissue inhibitor metalloproteinase (TIMP)1 were detected after treatment with ethanol or nebivolol. However, ethanol increased the expression of TIMP2, and this response was prevented by nebivolol. Our results provided novel insights into the mechanisms underlying the early stages of the cardiac injury induced by ethanol consumption. We demonstrated that Nox2/NADPH oxidase-derived ROS play a role in ethanol-induced lipoperoxidation and that this response was prevented by nebivolol. In addition, we provided evidence that MMPs are not activated in the early stages of ethanol-induced cardiac toxicity.

[Anti-heat shock protein 70 (anti - Hsp 70) antibodies in alcohol use disorder patients]

The expression of the most important chaperone protein - Hsp70 and autoimmunity directed against it is a risk factor of cardiovascular diseases, increased in subjects with alcohol use disorder (AUD). The aim of the study was to evaluate the level of anti-Hsp 70 protein antibodies (anti-Hsp 70) in sera of AUD patients during abstinence period. Material and methods. The study included 54 subjects with AUD diagnosed basing on DSM IV criteria. In the studied group clinimetric evaluation was performed, plasma lipids, basic transketolase activity in erythrocytes (TK), thiamine pyrophosphate (TPP) activation of transketolase and the level of anti-Hsp 70 antibodies were evaluated as well. Results. In AUD subjects anti-Hsp 70 level was decreased during abstinence period. During first month of abstinency it correlated negatively with total cholesterol concentration (rS=-0.8857, p=0.0188) and the percentage of TPP stimulation (rS=-0.5960, p<0.05), and during 6 months of abstinence with HDL cholesterol (rS=-0.6848, p=0.0289). After 1 year of abstinence anti-Hsp 70 correlated positively with basic TK activity (rS=0.9550, p=0.0008). Sex is an independent factor influencing anti-Hsp 70 level in AUD subjects (B=60.9469, p=0.0435). In multiple regression model including results of clinimetric evaluation and its effect on the level of anti-Hsp 70 antibodies in AUD patients during 1 month of abstinency anti-Hsp 70 correlated with TWEAK scale score (BETA=-1.4543, p=0.0144) and AUDIT score (BETA-=1.2255, p=0.0224). In 2-6 months of abstinency anti-Hsp 70 correlated with TWEAK score (BETA=1.1110, p=0.0418). After 1 year of abstinency anti-Hsp 70 correlated with AUDIT score (BETA=-1.2161, p=0.0210). Conclusion. The autoimmune reaction against Hsp 70 is decreased during abstinency in AUD patients. Its relation with plasma lipids and thiamine deficiency may lead to increased risk of cardiovascular disorders. TWEAK and AUDIT scoring seem to be most useful for clinimetric evaluation in the context of the role of anti-Hsp 70 antibodies.

[The importance of biochemical studies for practical forensic-medical expert examination]

Sudden death along with differential diagnosis of deaths from coronary heart disease and alcoholic cardiomyopathy is a challenging problem in practical forensic medicine. Relevant investigations demonstrated the possibility to address it using a battery of biochemical methods, such as measurement of blood glucose level in heart cavities, lactate dehydrogenase activity in myocardium, etc.

RETRACTED: Cardiac overexpression of alcohol dehydrogenase exacerbates chronic ethanol ingestion-induced myocardial dysfunction and hypertrophy: role of insulin signaling and ER stress

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). At the request of the University of Wyoming, this article has been retracted. The University of Wyoming's institutional investigation of the work authored by Dr. Jun Ren found evidence of data irregularities in Figures 2, 3 and 4 that affect the reported results and conclusions. All authors have been notified of the retraction of this article.

Study of oxidative stress and trace element levels in patients with alcoholic and non-alcoholic coronary artery disease

Alcohol consumption induces oxidative stress, and leads to lipid peroxidation. These effects have been linked to alcohol-related toxicity and diseases are considered relevant to alcohol-atherosclerosis interrelationship. Deficiency of many antioxidants and trace elements may impair the antioxidant defense leading to ethanol induced oxidative stress. In the present study, our aim was to investigate the lipid peroxidation, lipid profile, antioxidant enzymes and trace elements in patients with and without alcoholic coronary artery disease (CAD). Our study included 61 patients suffering from CAD, 124 patients suffering from alcoholic CAD with high to moderate alcohol intake, 75 controls were randomly selected for our study. Increased serum lipid peroxidation, total cholesterol, triglycerides, LDL cholesterol and copper levels were high while levels of HDL cholesterol, glutathione peroxdiase, superoxide dismutase, trace elements like Selenium and Zinc were low in high alcoholic CAD patients compared with moderate and non alcoholic CAD patients. The results obtained from present study indicate that high alcohol intake predicts low antioxidant enzyme and that trace element may contribute to the increased susceptibility for the development of CAD.

Myocardial Antioxidant Status in Chronic Alcoholism

BACKGROUND

Excessive ethanol intake is one of the most frequent causes of acquired dilated cardiomyopathy in developed countries. The pathogenesis is multifactorial, with the antioxidant imbalance of cardiac muscle being a potential factor. The current study evaluates myocardial antioxidant status in ethanol consumers and its relation to cardiac damage.

METHODS

The authors assessed superoxide dismutase, glutathione peroxidase, and glutathione reductase enzyme activities as well as the total antioxidant status capacity in myocardial samples obtained from organ donors with sudden death of traumatic or neurological origin. They studied 23 high-dose chronic alcohol consumers, 27 individuals with long-standing hypertension, and 11 healthy controls. Cardiomyopathy was defined according to standard functional and histological criteria.

RESULTS

Patients with dilated cardiomyopathy, either of alcoholic or hypertensive origin, showed increased myocardial superoxide dismutase activities compared with patients without cardiomyopathy (p < 0.001, both) and controls (p < 0.05, both). Total antioxidant status capacity and the activity of glutathione peroxidase and glutathione reductase enzymes were similar in all groups. Superoxide dismutase activity was related to the presence of cardiac enlargement and the degree of cardiac histological damage. The amount and type of alcoholic beverages as well as the nutritional status of the patients were not related to myocardial antioxidant activity.

CONCLUSIONS

The presence of dilated cardiomyopathy, of either alcoholic or hypertensive origin, is related to an increase in myocardial superoxide dismutase activity.

[Enzymatic markers in the alcoholic cardiomyopathy]

Alcoholic cardiomyopathy can ensue from heavy consumption of alcohol over a long period of time. The clinical features include dilatation of the left ventricle, poor myocardial contractility with reduced left ventricular ejection volume, raised tissue enzymes. In numerous experimental data has been observed increased generation of oxygen and ethanol free radicals, indicate that free radicals are implied in myocardial and hepatic damage. Ethanol administration also elicits hepatic disturbances in the availability of antioxidant defense. The resulting antioxidative stress leads to enhanced lipid peroxidation and can also affect other important cellular component.

Mutagenesis and characterization of specific residues in fatty acid ethyl ester synthase: a gene for alcohol-induced cardiomyopathy

Fatty acid ethyl ester synthase-III metabolizes both ethanol and carcinogens. Structure-function studies of the enzyme have not been performed in relation to site specific mutagenesis. In this study, three residues (Gly 32, Cys 39 and His 72) have been mutated to observe their role in enzyme activity. Gly to Gln, Cys to Trp and His to Ser mutations did not affect fatty acid ethyl ester synthase activity, but His to Ser mutant had less than 9% of control glutathione S-transferase activity. The apparent loss of transferase activity reflected a 28 fold weaker binding constant for glutathione. Thus, this study indicates that Gly and Cys may not be important for synthase or transferase activities however, histidine may play a role in glutathione binding, but it is not an essential catalytic residue of glutathione S-transferase or for fatty acid ethyl ester synthase activity.

[Changes in the enzymatic activity in the myocardium of patients with idiopathic and secondary dilated cardiomyopathy]

Myocardial biopsies from patients with dilated cardiomyopathy (DCMP) were studied histochemically. The patients were divided into the following groups: 1) idiopathic DCMP; 2) patients with postmyocarditis DCMP (an increase of lymphocytic-macrophagal elements in the myocardium); 3) secondary DCMP against alcoholic myocardial damage. Idiopathic and secondary DCMP are characterized by the following enzymatic changes: a decrease in the activity of the majority of oxidation-reduction mitochondrial enzymes, normal or increased activity of malate dehydrogenase, increased activity of lysosomal and microsomal enzymes. An increased activity of succinate dehydrogenase was observed only in patients who had previous myocarditis. Alterations in idiopathic and alcoholic DCMP were practically identical.

[Enzymatic diagnosis of alcoholism-induced damage of internal organs]

++Post-alcoholic lesion of liver, pancreas, and heart muscle was estimated by measurement of some enzymes activity. Alcoholic in-patients were divided into two groups in regard to the age and the length of the disease. The activity of enzymes in the blood was measured by kinetic methods using the RA-1000/Technicon analyser. It was shown that the increase of activity of alanine aminotransferase (AlAT), gamma-glutamyltransferase (GGTP), and alcohol dehydrogenase (ADH) may indicate the ++post-alcoholic liver damage, while increase of activity of alpha-+-amylase and ++leucine aminopeptidase (LAP) may be useful for the diagnosis of pancreas lesion, and creatine kinase (CK) as well as lactate dehydrogenase (LDH) for the evaluation of postalcoholic lesion of the heart muscle.

Alcoholic cardiomyopathy and sudden cardiac death

Seven hundred fifty-two cases of instantaneous sudden cardiac death were studied. Alcoholic cardiomyopathy was found in 127 cases (16.9%), predominantly in men under age 50 (73%). The heart was enlarged, with an average mass of 441 +/- 8 g. Light microscopy revealed uneven thinning and atrophy of the cardiomyocytes, with fatty infiltration and development of fatty tissue around the vessels of the left ventricle and interventricular septum, up to the subendocardial areas. In the majority of cardiomyocytes, electron microscopy showed atrophy of the myofibrils, pronounced dilation of the sarcoplasmic reticulum, lipids in the cytoplasm, mitochondriosis and an increased number of lysosomes and alterations of the mitochondria. Unchanged cardiomyocytes were characterized by hypertrophy and numerous ribosomes, and had developed a granular endoplasmic reticulum. Also observed were interstitial edema, an enlarged cardiomyocyte-capillary space, thinning of the capillary walls, flattening of the endothelium and a plethora and aggregation of erythrocytes. Decreases in mitochondrial enzyme activity were studied by enzyme histochemistry. Analogous pathologic changes may be individually present in other types of myocardial disease, but the complex of changes is specific for alcoholic cardiomyopathy. The frequency of alcoholic cardiomyopathy among victims of sudden death suggests that alcoholic cardiomyopathy is a risk factor for sudden cardiac death.

Ultrastructural and histochemical observations in human and experimental alcoholic cardiomyopathy

The morphologic features of alcoholic cardiomyopathy in human sudden death compared with those of experimental alcoholic cardiomyopathy (6 weeks of alcohol administration and simultaneous inhibition of catalase activity) proved to be nearly identical. Regular and similar alterations in alcoholic cardiomyopathy in both human victims of sudden death and experimental rats are described as a complex of alterations characteristic of alcoholic cardiomyopathy. This complex of changes was used as the basis for morphologic diagnosis of endomyocardial biopsy in two groups of patients: I) chronic alcoholics (second to third stages), and II) patients with clinically diagnosed congestive cardiomyopathy. Typical signs of alcoholic cardiomyopathy were found in 9 of the 11 patients in the first group and in 6 of 18 in the second group. The fact that the features of alcoholic cardiomyopathy were not found in all cases of chronic alcoholism supports the hypothesis that the administration of alcohol itself is not sufficient for the development of this disease. The level of enzyme activity in the metabolism of alcohol appears to be of great importance. This hypothesis is confirmed by experiments with rats in which this disease developed only when there was simultaneous alcohol administration and inhibition of catalase activity. Histochemical study showed that the alterations of enzyme (both energetic and alcohol metabolism) in rats were similar to those found in the biopsy specimens from patients with alcoholic cardiomyopathy. Certain questions regarding the pathogenesis of alcoholic cardiomyopathy are discussed.

[Blood serum creatine kinase in diseases of the cardiovascular system]

Serum creatine-kinase activity was above the upper normal limit in 40-80% of the 632 patients admitted to hospital for angina pectoris and deteriorating essential hypertension. The highest (4-6-fold) increase over the mean control values was associated with myocardial ischemia, paroxysmal tachycardia and hypertensive crises. Intramuscular injections were shown to be unrelated to increased incidence or magnitude of creatine-kinase activation in the examined patients. Creatine-kinase levels were particularly high in cases of cerebral stroke (a 7-fold increase above normal) and alcoholic cardiopathies (a 8-fold increase).

Increased MB-creatine kinase isoenzymes in an alcoholic population

Using agarose gel electrophoresis MB-creatine kinase (MB-CK) activity was examined in the serum of 120 patients with acute alcohol intoxication admitted to a detoxification ward. Total CK activity was increased in 67 percent of patients and MB-CK activity was increased in 8.3 percent. Alcoholic patients also were studied by Sephadex chromatography and, in seven cases, MB-CK was greater than three standard deviations from the normal. Thus, this study demonstrates that acute alcohol intoxication is associated with increased MB-CK activity. These findings raise the possibility that excessive alcohol ingestion may lead to acute myocardial injury.

Raised CK-MB isoenzyme after exercise in a patient with alcoholic myopathy

The relation between exercise, total serum creatine kinase activity, and serum creatine kinase MB isoenzyme in a patient with alcoholic myopathy was investigated. After a short-term exercise the serum values of creatine kinase MB isoenzyme rose to high levels within hours. This finding is important for obvious differential diagnostic reasons.

The effect of chronic ethanol consumption on enzyme activities of the energy-supplying metabolism and the alcohol-aldehyde oxidizing system in rat hearts

We investigated in rat hearts if chronic alcohol consumption causes an enzymatic adaption of the energy-supplying metabolism and/or of the alcohol-aldehyde metabolizing system. 16 rats were pair-fed with a liquid diet for 10 weeks. Ethanol was added to this diet to amount for 35% of calories in eight rats and was isocalorically replaced by saccharose in the control group. Selected enzyme activities of the glycolysis, the glycogenolysis, the beta-oxidation of fatty acids, the citric acid cycle and the alcohol-aldehyde oxidizing system were determined in the supernatants of the homogenized hearts. The intracellular redox state was assessed by measurement of the myocardial nicotinamide coenzymes. Enzyme activities of the alcohol-aldehyde metabolizing system did not alter after chronic alcohol intake. As we found that the capacity to oxidize acetaldehyde was much higher than the ability to oxidize ethanol we must question the role of acetaldehyde in inducing alcoholic cardiomyopathy. Chronic ethanol treatment significantly increased the activity of glyceraldehyde-3-phosphate dehydrogenase and decreased the activity of glycogen phosphorylase. The impairment of the hydroxyacylCoA dehydrogenase was not significant. The other measured enzyme activities did not alter, nor the intracellular redox state. The enzymatic adaption indicates an impaired glycogenolysis, an increased glycolysis, and probably a diminished beta-oxidation of fatty acids. We expect that the measurement of the responding enzyme activities in human endomyocardial biopsies should be a good tool to further classify cardiomyopathies according to biochemical criteria.

The measurement of enzyme activities in endomyocardial biopsies from patients with congestive (dilated) cardiomyopathy and specific heart muscle disease

50 patients with heart muscle disease have been investigated using routine invasive and non-invasive techniques, including endomyocardial biopsy. Enzyme activities in myocardial tissue obtained by biopsy have been measured in dilated cardiomyopathy and heart muscle disease and compared. Significant differences in enzyme activity have been found between dilated cardiomyopathy and alcoholic heart muscle disease when the groups are defined by detailed drinking histories. CPK (p less than 0.002), MDH (p less than 0.001), LDH (p less than 0.001) and alpha HBD (p less than 0.001). The changes in the enzyme levels may be an adaptive response to alcohol although serial study did not show a fall in enzyme activities after 3-6 months abstinence. Preliminary data furthermore indicates an association of the alpha HBD/LDH and LDH/CPK enzyme activity ratios and ejection fraction. This data supports the diagnosis of a specific heart muscle disease in response to alcohol excess.

Detection of alcoholic cardiomyopathy by serum enzyme and isoenzyme determination

Serum creatine kinase and lactate dehydrogenase isoenzymes were studied in 73 patients with alcoholism, including two patients with clinical alcoholic cardiomyopathy and 28 patients with haemodynamic evidence (systolic time interval abnormality) of disordered myocardial function. No isoenzyme abnormalities suggestive of myocardial injury were observed. We conclude that isoenzyme examination is unsuitable for the early detection of myocardial damage from alcohol.

Cardiac metabolsim: its contributions to alcoholic heart disease and myocardial failure

Changes in cardiac metabolism in myocardial failure and after alcohol ingestion are discussed. The main effect of alcohol ingestion is loss of cardiac contractility. Since heart muscle does not contain alcohol dehydrogenase, its toxicity is probably the result of a direct toxic effect of ethanol and acetaldehyde on the myocardial cell, possibly involving various membrane systems. Alcohol inhibits mitochondrial respiration and the activity of enzymes in the tricarboxylic acid cycle, and its interferes with both mitochondrial calcium uptake and binding. Ethanol profoundly affects myocardial lipid metabolism. Acetaldehyde diminishes myocardial protein synthesis and inhibits Ca++-activated myofibrillar ATPase. In myocardial failure, a series of possibilities may be responsible for the loss of contractility. Excitation-contraction coupling could be disturbed at the level of the sarcolemma, at the sarcoplasmic reticulum, at the mitochondria, and between calcium and the regulatory proteins. Deficiencies in Ca++ delivery systems of excitation-contraction coupling on the myosin ATPase activity could be responsible for the dimunition in cardiac contractility. Mitochondrial function may also be involved, since mitochondria from failing human hearts are defective with respect to respiratory control and calcium accumulation. Under certain conditions, the relationship of mitochondria to calcium sequestration is very important in influencing contractility. The involvement of contractile and regulatory proteins in myocardial failure cannot be excluded.