cytochalasin-b and Alcoholism

Alcohol abuse greatly increases the risk of various malignancies, including cancer of the liver and digestive tract. Although it is thought that this may be due, at least partially, to the mutagenic properties of ethanol, little is known about the genotoxic effects of ethanol in humans. We investigated the chromosomal damage in lymphocytes from 20 alcoholics and 20 controls using the micronucleus (MN) assay combined with fluorescence in situ hybridization (FISH) with a pancentromeric DNA probe capable of differentiating centromere positive (C+) from centromere negative (C-) MN. The frequency of MN in binucleate lymphocytes was significantly higher in alcoholics than in controls (12.0 +/- 5.4 and 7.6 +/- 1.6, respectively; P: < 0.05). FISH revealed significantly higher frequencies of C+ MN in alcoholics than in controls (8.2 +/- 4.8 and 3.4 +/- 1.4, respectively; P: < 0.05). In the alcoholics, no association was found between years of alcohol abuse and frequency of MN or C+ MN. However, age influenced MN and C+ MN frequency both in alcoholics and controls. These results indicate that alcohol abuse may well induce chromosome loss in humans, suggesting a possible aneugenic mechanism of alcohol. This effect could contribute to the health hazards related to alcoholism such as cancer risk.

Topics: Adult; Age Factors; Alcohol Drinking; Alcoholism; Case-Control Studies; Cell Nucleus; Cells, Cultured; Centromere; Chromosome Aberrations; Cytochalasin B; DNA Damage; Ethanol; Female; Humans; In Situ Hybridization, Fluorescence; Karyotyping; Lymphocytes; Male; Micronuclei, Chromosome-Defective; Middle Aged; Smoking; Time Factors

Phospholipase D has been shown to be a key enzyme in the signal transduction systems involved in neutrophil activation. In the presence of ethanol, the enzyme catalyzes a transphosphatidylation reaction through which phosphatidylethanol is formed instead of the normal product phosphatidic acid. The effects of ethanol on the formation of phosphatidylethanol and phosphatidic acid was studied in neutrophils from human alcoholics in vitro. Neutrophils were isolated and cellular lipids were labeled with [3H]oleate, whereafter the cells were preincubated with cytochalasin B. Subsequently, cells were stimulated with the chemotactic peptide formyl-Met-Leu-Phe in the presence of ethanol concentration ranging from 0 to 200 mM. In the presence of ethanol, both neutrophils from alcoholics and controls produced phosphatidylethanol, with a concomitant reduction of the production of phosphatidic acid. The amounts of phosphatidyl-ethanol and phosphatidic acid formed were dependent on the concentration of ethanol. In neutrophils from alcoholics, a higher apparent Km for the phospholipase D-mediated transphosphatidylation reaction was noted (58 mM ethanol compared with 28 mM in controls). The in vivo mass of phosphatidylethanol in recently drinking alcoholics was also analyzed in neutrophils. Measurable phosphatidyl-ethanol levels (average 5.6 pmol/10(8) neutrophils) were found in alcoholics up to 23 hr after the last intake of ethanol. Thus, in addition to the ethanol-induced changes in the normal production of phosphatidic acid, phosphatidylethanol accumulated in vivo in alcoholics may be expected to influence neutrophil function.

Topics: Adult; Alcoholism; Cells, Cultured; Cytochalasin B; Dose-Response Relationship, Drug; Ethanol; Fatty Acids; Female; Glycerophospholipids; Humans; Male; Middle Aged; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Phosphatidic Acids