Morphometric ultrastructural evaluation of secondary oocytes of mice receiving vincristine

Secondary oocytes from mice receiving vincristine in amounts corresponding to therapeutic doses in human, in neoplasm treatment, were evaluated morphometrically and ultrastructurally. In the group of animals treated with vincristine an increase of the volume fraction of vesicular complexes and a decrease of the volume fraction of fibrous material were observed. It has also been demonstrated that, in secondary oocytes from mice receiving vincristine, the number of both multivesicular bodies and vesicles falling to one vesicular complex profile was higher than in the control group. The present results suggest that vincristine applied to females, even in therapeutic doses, may affect egg cells.