The effect of acetaldehyde concentrations on the relative rates of formation of acetaldehyde-modified hemoglobins.

The effect of various concentrations of acetaldehyde (0, 0.05, 0.1, 0.25, 0.5, 1.0, and 5.0 mM) on the relative rates of formation of hemoglobin acetaldehyde adducts detected in fractions eluted from cation exchange high-pressure liquid chromatography (HPLC) was investigated. When the hemoglobin and acetaldehyde mixtures were incubated at 37 degrees C for various time intervals up to 24 hr, increased amounts of HbA1c could be observed after 2 hr incubation with 1 mM or greater concentrations of acetaldehyde, or after 4 hr incubation with at least 0.5 mM acetaldehyde. An increase in the HbA1a + b fraction was not observed with 4 hr incubation time until the acetaldehyde level reached 1 mM. The HPLC method detected no difference in minor hemoglobins from alcoholic and normal subjects. Incubation of red blood cells at 37 degrees C for 1 hr with six consecutive pulses of 0.05 mM [14C]acetaldehyde showed no differences in the amounts of minor hemoglobins determined chromatographically at various pulse intervals. However, the measure of the 14C-label incorporation into hemoglobin showed that adducts eluting in the HbA1a+b fraction were formed at a faster rate than those eluting in the HbA1c or HbA0 fraction, respectively. The specific activities of the HbA1a+b fractions at 2, 4, and 6 pulses were 34, 128, and 949 cpm/mg hemoglobin; those of the HbA1c fraction were 15, 58, and 174 cpm/mg hemoglobin. This evidence of modification of hemoglobin by physiological levels of acetaldehyde from 14C-label incorporation suggests that an assay more sensitive than chromatographic separation of adducts might be clinically useful in detecting alcoholism or monitoring alcohol detoxification programs.