Enumeration of 6‐thioguanine‐resistant T‐lymphocytes in the peripheral blood of nonhuman primates (cynomolgus monkeys)

Abstract
We have investigated the use of cynomolgus monkeys (Macaca fascicularis) as a model of somatic cell mutagenesis in non-human primates. Using techniques described by Albertini (Mutation Research 150:411–422, 1985) for similar studies in humans, the frequency of TG-resistant T-lymphocytes in the peripheral blood was determined in animals that were either untreated or treated with ethylnitrosourea. The frequency of TG-resistant cells in untreated males was (mean ± 5D) 6.0 ± 5.9 per 106 cells and for untreated females was 2.9 ± 2.7 per 106 cells. The spontaneous frequency of TG-resistant cells for all animals was 4.2 ± 4.44 per 106 cells. Maximum frequency of TG-resistant cells for two animals treated with a single I.P. dose of ENU was 45.1 and 77.9 per 106 cells. Substantial increases in frequencies of TG-resistant cells were not seen until at least 63 days after treatment. The TG-resistant phenotype of clones isolated in the assay was stable after growth for 2 weeks in the absence of selective agent. Many of the TG-resistant clones selected were frozen for future molecular analysis.