title: PIGRET assay can detect mutagenicity of ethyl methanesulfonate much earlier than RBC Pig-a assay.
abstract: The comparison between the original red blood cell (RBC) Pig-a assay, which measures Pig-a mutant RBCs, and the PIGRET assay, which uses reticulocytes, was conducted using in vivo mutagenesis by ethyl methanesulfonate (EMS) as a part of a collaborative study by the Mammalian Mutagenicity Study Group in the Japanese Environmental Mutagen Society. Three dose levels of EMS (180, 360, and 720mg/kg) were administered once by oral gavage to 8-week-old male Crl:CD(SD) rats, and peripheral blood was sampled at 0 (1 day before dosing), 1, 2, and 4 weeks after dosing with EMS. As a result, a statistically significant increase in the mutant frequency of the Pig-a gene was observed from 2 weeks after dosing and a higher value was obtained on week 4 at the highest dose only in the RBC Pig-a assay. In the PIGRET assay, on the other hand, a statistically significant increase in Pig-a mutant frequency was obtained at the highest dose from 1 week after dosing, and it decreased on weeks 2 and 4 compared to the value at week 1. The Pig-a mutant frequency appeared to reach a plateau 1 week after dosing in the PIGRET assay and it might continue to increase even after week 4 in the RBC Pig-a assay. These results indicate that the PIGRET assay can detect Pig-a mutants much earlier than the original RBC Pig-a assay, and it can enable judgement of mutagenicity of EMS within 1 week after a single dosing.
authors.affiliation: Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13, Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan. Electronic address: itoh.satoru.n5@daiichisankyo.co.jp.
authors.forename: Satoru
authors.initials: S
authors.lastname: Itoh
authors.affiliation: Biologics Pharmacology Research Laboratories, Daiichi Sankyo Co., Ltd., 1-2-58, Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan.
authors.forename: Chiharu
authors.initials: C
authors.lastname: Hattori
authors.affiliation: Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13, Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan.
authors.forename: Shiho
authors.initials: S
authors.lastname: Nakayama
authors.affiliation: Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13, Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan.
authors.forename: Akiharu
authors.initials: A
authors.lastname: Hanamoto
mesh_terms: D000818:Animals; D004912:Erythrocytes / Q000187:drug effects*; D005020:Ethyl Methanesulfonate / Q000633:toxicity*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D009152:Mutagenicity Tests / Q000379:methods*; D009153:Mutagens / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012156:Reticulocytes / Q000187:drug effects*
chemical_list: D008565:Membrane Proteins; D009153:Mutagens; C080086:phosphatidylinositol glycan-class A protein; D005020:Ethyl Methanesulfonate
keywords: In vivo mutation assay; Pig-a gene; Red blood cells; Reticulocytes