Detection of metrial gland cells in rat cervix after delivery by smear method

It has been reported that the metrial glands, which form yellowish-white masses on the mesometrial triangle after pregnancy, coincide with the number of implants in the rat. In this study, the migration of the metrial gland cells (MGC) from the metrial glands to the endometrium after placental desquamation was investigated by the smear method. In smeared specimens, MGC appeared as large round cells with an unstained nucleus (a large binucleate cell was frequently seen), surrounded by a pinkish rim of cytoplasm, with PAS-staining; or appeared as a large reddish violet nucleus surrounded by dark violet cytoplasm with Giemsa staining. Numerous MGC were observed on the endometrium on the mesometrial side after artificial desquamation of the placenta on day 20 of pregnancy and day 0 of delivery. Further, MGC were observed on the endometrium on the antimesometrial side or in the cervix (including the internal and external orifice of the uterus) on day 0 of delivery, but no MGC could be detected in the cervix or on the antimesometrial side either during the period of placental signs (days 11-13) or on day 20 of pregnancy. Although MGC disappeared rapidly after delivery, slight traces of MGC remained on the mesometrial side until day 3 after delivery. In the case of abortion, MGC were observed in the cervix on the day of vaginal bleeding. In view of these results, it is considered that confirmation of MGC on the endometrium or the cervix provides evidence of abortion or delivery.