title: Carcinogenic tryptophan pyrolysis products in human lens.
abstract: Mutagenic and carcinogenic tryptophan pyrolysis products, 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), have been identified in human cataractous lenses, but not in young bovine lenses. The amounts of Trp-P-1 and Trp-P-2 in senile cataractous lenses were 156.34 +/- 35.63 fmol (mean +/- S.D., n = 10) and 128.27 +/- 40.45 fmol (n = 10), respectively, while those of Trp-P-1 and Trp-P-2 in diabetic cataractous lenses were 158.29 +/- 40.06 fmol (n = 10) and 150.34 +/- 23.77 fmol (n = 10), respectively. In both senile and diabetic cataractous lenses, the concentrations of Trp-P-1 and Trp-P-2 in the insoluble protein fraction (fmol mg-1 protein) were significantly higher than those in the water-soluble protein fraction. Moreover, proteinase-K treatment of lens protein before extraction with methylene chloride significantly increased the recoveries of Trp-P-1 and Trp-P-2. These results clearly indicate that carcinogenic tryptophan pyrolysis products, gamma-carboline derivatives, are present in human cataractous lenses and that these fluorescent carcinogens are significantly concentrated in the insoluble lens proteins.
authors.affiliation: Department of Hygiene and Preventive Medicine, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Manabe
authors.forename: O
authors.initials: O
authors.lastname: Wada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002243:Carbolines / Q000032:analysis*; D002273:Carcinogens / Q000032:analysis*; D002386:Cataract / Q000150:complications / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D048909:Diabetes Complications; D005260:Female; D006801:Humans; D007908:Lens, Crystalline / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009153:Mutagens / Q000032:analysis
chemical_list: D002243:Carbolines; D002273:Carcinogens; D009153:Mutagens; C019133:3-amino-1-methyl-5H-pyrido(4,3-b)indole; C019132:3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole