Results of rat Pig-a/PIGRET assay with a single dose regimen of 1,3-propane sultone and 2-acetyl aminofluorene

• Published in: Mutation research. Genetic toxicology and environmental mutagenesis 2016-11, Vol.811, p.75-79
• Main Authors: Shigano, Miyuki, Ishii, Nana, Takashima, Rie, Harada, Hideki, Takasawa, Hironao, Hamada, Shuichi
• Format: Article
• Language: English
• Subjects: 1,3-propane sultone; 2-acetyl aminofluorene; In vivo mutation assay; PIGRET assay; RBC Pig-a assay
• ISSN: 1383-5718; 1879-3592
• DOI: 10.1016/j.mrgentox.2016.04.001

•The mutagenicities of 1,3-PS and 2-AAF were evaluated by a Pig-a assay.•1,3-PS induced Pig-a mutant RBCs and RETs in rats.•2-AAF induced neither Pig-a mutant RBCs nor RETs in rats.•The PIGRET assay could detect Pig-a mutants earlier than the RBC Pig-a assay. The Pig-a assay is a useful in vivo mutation detecting test and is easier to perform than the in vivo transgenic mutation assay. This assay is now recognized to be able to detect a number of mutagenic chemicals administered to rats in sub-acute or sub-chronic dose studies. The present investigation was conducted to evaluate the usefulness of peripheral blood Pig-a assays with total red blood cells (RBC Pig-a assay) and with reticulocytes (PIGRET assay) using two genotoxic rodent carcinogens, 1,3-propane sultone (1,3-PS) and 2-acetylaminofluorene (2-AAF). Male rats were orally administered a single dose of each test compound, and both the RBC Pig-a and PIGRET assays were performed using flow cytometry to measure the Pig-a mutant frequency (MF) before and after dosing on Days 8, 15 and 29. In the experiment with 1,3-PS, significant increases in Pig-a MF were observed from Day 15 and Day 8 in the RBC Pig-a and PIGRET assays, respectively. The results of both assays demonstrated that the increases in Pig-a MF were detectable after a single treatment with 1,3-PS. Furthermore, the difference in the kinetics of the increase in Pig-a MF between the RBC Pig-a and PIGRET assays with 1,3-PS suggests that the PIGRET assay has an advantage in detecting the mutant erythrocytes earlier than the RBC Pig-a assay. In contrast, no significant increases were observed in the Pig-a assays using either RBC or reticulocytes with 2-AAF. The negative results in both assays with 2-AAF may indicate the limitation of the single dose method; however, further investigation at higher doses is necessary to determine limitation of the single dose method.