6-Methoxy-tetrahydro-beta-carboline and melatonin in the human retina

The presence of two 5-methoxyindoles, 6-methoxy-1,2,3,4-tetrahydro-beta-carboline (6-MeO- THBC ) and melatonin was demonstrated in human retinae using a highly specific gas chromatographic mass spectrometric method from eyes affected with various ocular diseases. Both compounds were found to occur in similar quantities. 6-MeO- THBC is a newly-identified endogenously-occurring retinal compound possibly acting as a neuromodulator. The importance of 6-MeO- THBC and other beta-carbolines especially compared to other 5-methoxyindoles is discussed.