Chromosome aberrations in metaphase II oocytes of Chinese hamster (Cricetulus griseus). I. The sensitivity of the pre-ovulatory phase to triaziquone

In previous investigations with triaziquone, cyclophosphamide, amethopterin and X-rays we showed that the pre-ovulatory stages of mice are sensitive to the induction of numerical and structural chromosome aberrations. In the present investigation, we studied the problem whether or not this sensitivity is restricted to mice. Two doses of triaziquone were injected intraperitoneally to Chinese hamster females at different intervals before ovulation. The ovulated oocytes were collected from the ampulla and analyzed at the metaphase II stage. After treatment with triaziquone, the frequency of both numerical and structural aberrations was significantly increased over the control values. The proportion of induced structural anomalies was higher than that of the numerical ones. Chinese hamsters were less sensitive to the induction of structural and especially numerical anomalies compared with the findings with one strain of mouse.