These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Enhancing effect of heterocyclic amines and beta-carbolines on UV or chemically induced mutagenesis in E. coli. Author: Shimoi K, Kawabata H, Tomita I. Journal: Mutat Res; 1992 Aug; 268(2):287-95. PubMed ID: 1379334. Abstract: Most heterocyclic amines and beta-carbolines--harman, norharman, harmine, harmaline--enhanced UVC (254 nm) induced mutagenesis without microsomal activation in E. coli B/r WP2. 3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) was most effective and increased UVAB (295-400 nm) induced mutations as well as UVC induced ones. Trp-P-1 enhanced the frequencies of mutations induced by not only UV but also 4-nitroquinoline-1-oxide (4NQO) or 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF2), while it showed little effect on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or gamma-ray induced mutagenesis. Trp-P-1 decreased the survival of UVC irradiated cells of CM571recA. However, these effects of Trp-P-1 on UVC induced mutagenesis and lethality were not observed in WP2suvrA which is excision repair deficient. The alkaline sucrose gradient sedimentation analysis demonstrated that Trp-P-1 blocked the incision step in DNA excision repair. Further, pretreatment with Trp-P-1 before UVC irradiation showed no effect on UVC induced mutagenesis. Similar effects were also seen in the case of harman or norharman. These results suggest that heterocyclic amines and beta-carbolines inhibit DNA excision repair directly or indirectly, thus enhancing UV or chemically induced mutagenesis.[Abstract] [Full Text] [Related] [New Search]