EMISSION-SPECTRA OF COLONIC TISSUE AND ENDOGENOUS FLUOROPHORES

Autofluorescence emission spectra of normal, adenomatous, and malignan t tissues of the colon were compared to that of known fluorophores to indicate the possible causes of tissue fluorescence. Data were collect ed from normal mucosa (n = 18), adenomatous polyps (n = 32), and adeno carcinoma (n = 18) of the colon. A range of cellular and extracellular fluorophores (elastin, collagen, flavin adenine dinucleotide, nicotin amide adenine dinucleotide, phenylalanine, pyridoxal 5' phosphate, try ptophan, and tyrosine) were similarly examined using a spectrofluorome ter with emission and excitation spectrometers. Emission intensities w ere plotted against wavelength. Wavelengths of peak emission and the w idth of each peak at half its maximum intensity were measured. Colonic tissue gave four major emission peaks, the wavelengths of which were independent of tissue histology. Tryptophan and collagen type IV appea red to be responsible for two of the peaks. It is possible that NADH m ay be the cause of a third emission maxima.