title: Detection of vincristine-induced hyperploidy in meiotic II metaphases of male Chinese hamsters.
abstract: Induction of hyperploidy in germ cells of male Chinese hamsters treated with vincristine at dose levels of 0.25, 0.50 or 0.75 mg/kg of body weight was investigated. Animals were killed at 6, 24, 48, 72 and 96 h after administration of the chemical by a single intraperitoneal injection. The testes were removed and processed for spermatogonial, meiotic I, and meiotic II metaphases. Significantly increased frequencies of hyperploidy were obtained in meiotic II cells harvested 6, 24 and 48 h but not 72 and 96 h after treatment, indicating the importance of multiple sampling times. Analysis of spermatogonial cells shows that the frequencies of hyperploidy in the treated samples were comparable to those of controls. Limited sampling times used in the present study as well as small sample size or possible loss of hyperploid cells may be responsible for the negative findings for spermatogonial cells. Examination of meiotic I cells from 53 animals reveals the presence of one animal with an elevated level of hyperploidy unrelated to the vincristine treatment.
authors.affiliation: Genetic Toxicology Branch, Food and Drug Administration, Washington, DC 20204.
authors.forename: C W
authors.initials: CW
authors.lastname: Sheu
authors.forename: J K
authors.initials: JK
authors.lastname: Lee
authors.forename: C A
authors.initials: CA
authors.lastname: Arras
authors.forename: R L
authors.initials: RL
authors.lastname: Jones
authors.forename: K S
authors.initials: KS
authors.lastname: Lavappa
mesh_terms: D000818:Animals; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D007621:Karyotyping; D008297:Male; D008540:Meiosis; D008677:Metaphase; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D011123:Polyploidy; D013093:Spermatogonia / Q000187:drug effects / Q000473:pathology; D013737:Testis / Q000187:drug effects / Q000473:pathology*; D014750:Vincristine / Q000633:toxicity*
chemical_list: D009153:Mutagens; D014750:Vincristine