Measurement of lactate levels in serum and bile using proton nuclear magnetic resonance in patients with hepatobiliary diseases: its utility in detection of malignancies.

Proton nuclear magnetic resonance (1H-NMR) has been utilized for qualitative and quantitative measurement of the components of nonhomogeneous biological specimens, as it can analyze sensitively the chemical structure of organic compounds without pretreatment of the materials. Levels of lactate in serum and bile were measured by 1H-NMR in healthy volunteers and patients with non-malignant or malignant diseases of the liver and biliary tract, and the usefulness of such measurements for the diagnosis of hepatobiliary malignancies was determined. The mean (+/- SD) serum lactate levels were 0.52 +/- 0.33 mmol/l in five healthy volunteers, 1.38 +/- 1.59 mmol/l in 30 patients with non-malignant diseases and 2.95 +/- 2.00 mmol/l in 21 patients with malignant diseases, the differences among the three groups being significant. Biochemical enzymatic measurement of serum lactate levels revealed no such difference. In bile, the spectrum of lactate was observed in all of 16 patients with malignant diseases, but in none of two healthy volunteers and 12 patients with non-malignant diseases. The mean time required for the measurement was 36.77 min for serum and 6.40 min for bile. The measurement of lactate levels in serum and bile using 1H-NMR may be useful for the detection of hepatobiliary malignancies.