Observation of estrous cycle in sexual maturation and ovariectomized fe-male ICR mice / 中国病理生理杂志

ABSTRACT

AIM:To observe the characteristics of estrous cycle of female ICR mice and ovariectomized mice that had reached sexual maturity stage .METHODS:ICR mice were randomly divided into 3 groups, normal group, sham operation group and ovariectomized group .After ovariectomy and sham operating , at the 8th day, the mice were taken vagi-nal smears twice daily (0900 and 1600) for 12 consecutive days.The feature of vulva in the mice and vaginal smear cy-tology, occurrence rate of regular estrous cycle , duration of estrous cycle and each stage duration of estrous cycle were re -corded and observed .RESULTS:The characteristics of estrous cycle in normal group and sham operation group were simi-lar.Nearly 85%of the ICR mice in sexual maturity stage showed regular estrous cycle .The majority manifested 6-day cy-cle (83%), and only a small number exhibited 5-day cycle (17%).Compared with 5-day group, the duration of oestrus was significantly increased in 6-day group (P<0.05).The number and kind of the cells in vaginal smear were a little dif-ferent between 5-day and 6-day groups.The ovariectomized mice which showed irregular estrous cycle (76%) were charac-terized by continuous diestrus .CONCLUSION:Female ICR mice have the strain characteristics of estrus cycle .