title: The effect of methylxanthines on chromosomes of human lyphocytes in culture.
abstract: The effect of caffeine (I,3,7-trimethylxanthine), theophylline (I,3-dimethylxanthine), theobromine (3,7-dimethylxanthine), paraxanthine (I,7-dimethylxanthine) I-methylxanthine, 3-methylxanthine, and 7-methylxanthine added at the 48th h on the chromosomes of human lymphocytes in 72-h cultures has been investigated. Caffeine and the dimethylxanthines cause breakage at 750 mug/ml, with caffeine the most, and paraxanthine the least clastogenic. I-Methylxanthine and dimethylxanthines with a methyl group in the I-position are the most effective in depressing mitotic indices. No chromosome damage was exhibited by the monomethylxanthines.
mesh_terms: D002110:Caffeine / Q000494:pharmacology; D002478:Cells, Cultured; D002875:Chromosomes / Q000187:drug effects*; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000648:ultrastructure; D008938:Mitosis / Q000187:drug effects; D009153:Mutagens / Q000494:pharmacology*; D013805:Theobromine / Q000494:pharmacology; D013806:Theophylline / Q000494:pharmacology; D013997:Time Factors; D014970:Xanthines / Q000494:pharmacology*
chemical_list: D009153:Mutagens; D014970:Xanthines; D002110:Caffeine; D013806:Theophylline; D013805:Theobromine