That is, it neither inhibits nor enhances the change in size or histology (epithelial cornification) of the cervix, but it results in progressive histopathological responses in the uterus. Why neonatal DES exposure permanently alters estrogen responsiveness in the uterus, but not in the cervix, of adult hamsters is not yet known. A related question is what drives the DES-specific difference in size and histology of cervical regions from the adult hamsters with ovaries (see Figs. 7 and 8). The responses observed in intact versus ovariectomized and estrogen-replaced animals seem to indicate a differential effect of the two neonatal treatment regimens on ovarian factors. In fact, preliminary results indicate that neonatal DES treatment does disrupt morphogenesis of the hamster ovary to a greater extent than does neonatal E2 treatment.
Whether neonatal DES treatment disrupts morphogenesis of the hamster ovary by a direct or indirect mechanism and how its follicular development and steroidogenic function may be disrupted are currently under investigation. In conclusion, both the early and long-term development of the cervix in intact hamsters was differentially disrupted by neonatal exposure to the same high dose of DES versus E2. The extent of this phenomenon in adult animals may be caused, at least in part, by differing degrees of altered ovarian function between the two neonatal treatment groups. However, the mechanisms and ovarian agents responsible for differential disruption in the postpubertal cervix are not yet known. Relevant to this topic, and in contrast to what was found in the hamster uterus, the response of the adult hamster cervix to chronic estrogen stimulation did not differ between the two neonatal treatment groups or between the two neonatal treatment groups and the control group. Future efforts in this experimental system should use a range of lower, environmentally relevant doses of DES, E2, plus other suspected EDs and should continue to probe for differences in molecular dynamics among specific reproductive tract regions (cervix, uterus, oviduct, and ovary). canadian health care mall