title: Red blood cell Pig-a assay and PIGRET assay in rats with azathioprine.
abstract: A new in vivo gene mutation assay has been developed based on the phosphatidylinositol glycan anchor biosynthesis, Class A gene (Pig-a in rodents) as an endogenous reporter. Using this Pig-a assay, the in vivo mutagenicity of a single dose of azathioprine (Aza) was investigated in red blood cells (RBC Pig-a assay) and reticulocytes (PIGRET) of rats. Eight-week old male rats were orally dosed once with Aza at 50, 100 and 200mg/kg or ethylnitrosourea (ENU) at 10 and 40mg/kg as a positive control. Because 4 out of 6 animals at 200mg/kg of Aza died 3days after the dosing, this dose group was excluded for analyses. The frequencies of Pig-a mutants in RBCs and reticulocytes (RET) were evaluated once a week for 4 weeks after the treatment. With a single exposure to ENU, the frequencies of Pig-a mutants in both RBCs and RETs increased in a time- and dose-dependent manner. In contrast, with Aza small effects that were not statistically significant were observed in rats at 21 and 14days in the RBC Pig-a and PIGRET assays respectively. Based on the present results, the mutagenic potential of Aza is negligible after single oral administration in rats.
authors.affiliation: Drug Safety Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.
authors.forename: Ikuma
authors.initials: I
authors.lastname: Yoshida
authors.affiliation: Drug Safety Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.
authors.forename: Akemi
authors.initials: A
authors.lastname: Matsumoto
authors.affiliation: Drug Safety Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Sakai
authors.affiliation: Drug Safety Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Harada
authors.affiliation: Drug Safety Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan. Electronic address: tsuneo.hashizume@takeda.com.
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Hashizume
mesh_terms: D000818:Animals; D001379:Azathioprine / Q000633:toxicity*; D004912:Erythrocytes / Q000187:drug effects*; 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; D001379:Azathioprine
keywords: Azathioprine; Gene mutation; Pig-a gene; Red blood cells; Reticulocytes