Indole-3-acetic acid in human cerebrospinal fluid: identification and quantification by mass fragmentography.

Indole-3-acetic acid has been identified in human cerebrospinal fluid by the gas chromatographic-mass spectrometric technique called mass fragmentography. A specific and sensitive method for quantitative determination of indole-3-acetic acid down to 2 nanograms per milliliter of cerebrospinal fluid has been developed. Samples of cerebrospinal fluid from 24 patients with depression contained 6.1 +/- 3.1 (range 2.6 to 15.8) nanograms of indole-3-acetic acid per milliliter.