Blood acetaldehyde in alcoholized rats and humans during inhalation of carbon disulphide vapor

Summary

Exposure of rats to 20 ppm CS₂ (the current MAC in various countries) for 8 h was followed by i.p. administration of 2 g/kg ethanol (blood level: 3-1‰) and another up to 4-h exposure to the same concentration of CS₂. During the second exposure the acetaldehyde concentration increased significantly, the rise representing one third of the control values. Inhalation of 400 ppm CS₂ for the same period, or 8-h exposures at 400 ppm CS₂ on 5 consecutive days produced only a slight additional increase in acetaldehyde. The increased appearance of acetaldehyde in blood is considered to be due to inhibition of aldehyde dehydrogenase by CS₂. This conclusion was derived from the significant lag in the clearance rate of acetaldehyde given i.v. (1 mmol/kg) after exposure at 400 ppm CS₂/8 h, involving an increase of the excretion half-life of acetaldehyde (1 min, 45 s in the controls) to 2 min, 24 s. The finding thus obtained could be reproduced in man (adult males). At a blood alcohol concentration of approximately 0.75‰, maintained at this level for 8 h, the blood acetaldehyde concentration was found to be approximately 6 × 10⁻³‰; it rose significantly by about 50% during simultaneous 8-h exposure of the test subjects to a nonfluctuating, analytically defined concentration of 20 ppm CS₂. When increasing the dose Of CS₂ to 40 ppm and 80 ppm for 8 h, only a slight additional increase was noted. Administration of ethanol (ca. 0./5‰) for 8 h, instituted at 16 h after 8-h inhalation of 20 ppm CS₂, produced a rise in blood acetaldehyde to slightly more than twice the control value. An approximately identical quantitative effect was observed after exposure to 20 ppm on 5 consecutive days at the same time of the day (8.00 a.m. - 4.00 p.m.). Under the conditions employed, there was no evidence of any subjective or objective signs of alcohol intolerance in terms of an “antabuse syndrome” in the experiments. Inhalation of CS₂ vapor failed to exert a significant effect on the pharmacokinetic behavior of ethanol in with a blood alcohol content up to 0.8%., contact with CS₂ is not likely to give rise to a CS₂-alcohol reaction, provided the concentrations of CS₂ encountered in the work environment are within the range of the MAC.