H-1-NMR SPECTROSCOPIC ANALYSIS OF HUMAN URINE - PERIODIC VARIATION OFTRIMETHYLAMINE OXIDE EXCRETION

We used H-1-NMR to study the constituents of the urine from a female v olunteer who had an unidentified complaint syndrome (chief complaints: discomfort of scapular region, abdominal distention and exhaustion). The pH dependence of the chemical shift of some constituents was inves tigated for signal assignments, and the intense peak at about 3.3 ppm was assigned to trimethylamine oxide (TMAO). We measured the concentra tion of the constituents of urine, and TMAO excretion in the urine ove r a three week time period. The TMAO excretion fluctuated in a cycle o f about 2 days. The average excretion determined (3.8 mmole/day) is co nsiderably higher than data of healthy humans that had been previously reported (0.3 to 0.5 mmole/day).