Regulation of the formation of stable adducts between acetaldehyde and blood proteins

Vitamin B6 metabolism and binding to proteins in the blood of alcoholic and nonalcoholic men

Blood obtained from nonalcoholic and alcoholic subjects was incubated with 100 nM [3H]pyridoxine to study its uptake and metabolism by erythrocytes and the binding of vitamin B6 metabolites to proteins in plasma and erythrocytes. Erythrocytes of the alcoholics accumulated tritium faster than those of the controls; however, they contained the same total amount of tritiated compounds by 15 min. After incubation for 30 min, the erythrocytes had converted most of the pyridoxine to pyridoxal phosphate and pyridoxal. Pyridoxal-P remained in the erythrocytes, and approximately 40% of the pyridoxal diffused into the plasma. [3H]Pyridoxal and [3H]pyridoxal-P levels in the erythrocytes and plasma of the alcoholics were similar to those in the controls. However, dialyzed hemolysates of the alcoholics had more [3H]pyridoxal and a lower percentage of [3H]pyridoxal-P than those of the controls. The total concentration of plasma pyridoxal-P was lower in the alcoholics than in the controls and did not change upon incubation of whole blood with pyridoxine or upon dialysis. The erythrocytes of the alcoholics and controls had similar concentrations of pyridoxal-P that increased 2.5-fold upon incubation of whole blood with pyridoxine for 30 min and returned to the initial concentrations upon dialysis. The amount of [3H]pyridoxal and [3H]pyridoxal-P bound to protein was assessed by treating hemolysate and plasma samples with borohydride before dialysis. More 3H was bound to protein in the erythrocytes than in the plasma. The amount of protein-bound 3H in the erythrocytes of the alcoholics was lower than that of the controls, whereas the amount of protein-bound 3H in plasma was similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Laboratory markers of ethanol intake and abuse: a critical appraisal

Laboratory markers for ethanol intake and abuse and chronic alcoholism currently in use have been critically reviewed. The merits and pitfalls of each test have been evaluated. The clinical use of the new test of carbohydrate-deficient transferrin has been particularly emphasized. Carbohydrate-deficient transferrin currently provides the highest specificity and sensitivity of all commonly used markers of alcoholism.

Ethanol elimination among different racial groups

This study examined the relationship between ethanol elimination and race, specifically exploring differences among Alaskan Natives, American Indians, and whites. Native Americans, believed to be of recent Asian origin, were expected to eliminate alcohol faster than whites. The data suggested that both Native American men and women eliminated alcohol faster than whites. A relationship was also found between age, gender, and rate of alcohol elimination. The implications of these findings were reviewed and specific needs for future research were noted.

Protein-acetaldehyde adducts in serum of alcoholic patients

Enzyme-linked immunosorbent assay (ELISA) was used to detect the presence of protein-acetaldehyde adducts (-AAs) in human serum samples. Two methods were compared: (1) direct ELISA: samples, rabbit anti-hemocyanin-AA IgG, and beta-galactosidase (beta-gal) conjugated goat anti-rabbit serum IgG added to a 96-well ELISA plate in a stepwise manner; and (2) two-site or sandwich ELISA: serum samples added to an ELISA plate that had been precoated with anti-hemocyanin-AA IgG (the capture antibody) and incubated stepwise with biotinated anti-hemocyanin-AA IgG (the signal antibody) and avidin-beta-gal conjugates. Serum protein-AA levels were then assayed by bound beta-gal activities at OD405. When human hemoglobin (Hgb)-AA was used as a model protein-AA for the sandwich ELISA, the EC50 (estimated concentration that corresponds to 50% of the OD405 response range) was 7 ng/ml. Direct ELISA was less sensitive (EC50 of 120 ng/ml). Adding control human serum to Hgb-AA increased the EC50 of the direct ELISA more than the sandwich ELISA. Intra- and interassay coefficients of variance for sandwich ELISA were both about 8%. Detection of Hgb-AA by sandwich ELISA was highly specific. The above results with anti-hemocyanin-AA IgG were also obtained when anti-myoglobin-AA IgG was used in sandwich ELISA. Using sandwich ELISA and anti-hemocyanin-AA IgG, OD405 for sera of control subjects and alcoholic patients were 0.036 +/- 0.033 (+/- SEM, n = 28) and 0.150 +/- 0.088 (n = 28), respectively. Serum protein-AAs reacted more strongly with anti-myoglobin-AA IgG than anti-hemocyanin-AA IgG.(ABSTRACT TRUNCATED AT 250 WORDS)

Covalent binding of acetaldehyde to type III collagen

Incubation of neutral salt soluble type III pN-collagen with [14C]acetaldehyde in vitro resulted in the formation of spontaneously stable acetaldehyde-protein adducts. This reaction occurred primarily at lysine residues and it was not affected by 0.2-2 mM concentrations of ascorbate but addition of sodiumcyanoborohydride increased the stable adducts by 3-5-fold. When confluent cultures of human skin fibroblasts were incubated with physiologically relevant concentrations of acetaldehyde, it became covalently bound to type III procollagen secreted into the medium. We propose that acetaldehyde binding to collagen fibrils occurs in vivo following chronic alcohol consumption.

International Commission for Protection against Environmental Mutagens and Carcinogens. ICPEMC Working Paper No. 15/3. Human acetaldehyde levels: aspects of current interest

The determination of acetaldehyde levels in blood and other tissues is a difficult task, and depends on the method used. Different methods and their pros and cons are discussed in detail. Quantitative results are shown for endogenous acetaldehyde levels and for acetaldehyde levels during alcohol intoxication. One article pertains to acetaldehyde bound to blood and tissue proteins.