RESUMO
Growth rate of follicles and effects of administration of oestradiol valerate (EV), testosterone propionate (TP) and aminoglutethemide phosphate (AGP) on the development of ovarian follicles of the adult musk shrew were investigated. The follicular growth rate was estimated by mitotic index before and 2 hr after colchicine treatment to the shrews. Mitotic index of granulosa cells increased linearly with the increase in the follicular diameter. The calculated mean duration of mitosis was 0.48 hr. The mean time taken for follicle to pass from primary follicle stage to preovulatory stage was estimated to be 12 days. Treatment of both the steroids EV and TP, failed to produce any noticeable effect on the atretic follicle of the musk shrew. The results indicate that neither EV or TP, nor the potent steroid inhibitor AGP had any influence on the growth of large follicles in this primitive eutherian mammal.