Clinical application of breath analysis for dimethyl sulfide following ingestion of DL-methionine.

After overnight-fasting, the concentration of dimethyl sulfide in expired alveolar gas (alv-DMS) was determined serially following ingestion of 2 g of DL-methionine in normal subjects and patients with liver diseases. Alv-DMS rose to a peak in 30 to 90 min, declined markedly within 3 h, and then decreased gradually. Half-disappearance times (T 1/2) (mean +/- S.E. min) in each experimental group were: normal (N = 9) 61.7 +/- 4.7, acute hepatitis (N = 6) 62.5 +/- 6.8, chronic hepatitis (N = 10) 84.0 +/- 13.0, and liver cirrhosis (N = 13) 159.2 +/- 30.4, respectively. Cirrhotics had a T 1/2 significantly longer than that of the other three groups: vs. normal P less than 0.02, vs. acute hepatitis P less than 0.05, and vs. chronic hepatitis P less than 0.05. T 1/2 of alv-DMS following ingestion of DL-methionine seems to be of clinical interest.