Study On Effects Of Intercostal Nerve Transection In Rats With Hyperplasia Of Mammary Glands

ObjectiveTo study the effect and relative mechanism of cutting off the seventh intercostalnerve and the eighth intercostal nerve in the right side on mammary gland hyperplasiain SD rats.Methods40SD rats were randomly divided into4groups: normal group, model group, theintercostal nerve transection group and ovariectomized group. Combined estradiolbenzoate with progesterone by intramuscular injection to establish a rat model ofmammary gland hyperplasia. The diameter and height of the third nipple by right sidein each group were measured at2weeks,4weeks and6weeks, respectively. Themammary gland tissues were cut off and stained by HE to observe the morphologicalchanges of the breast tissue. The mRNA levels of estradiol receptor and progestogenreceptor in breast tissue were measured by real time PCR at2weeks,4weeks and6weeks. The protein levels of estradiol receptor and progestogen receptor in breasttissue were measured by western blot at6weeks.ResultsThe rat model of mammary gland hyperplasia was successfully established. Thediameter and height of right side of the third nipple were measured. The diameter andheight in the intercostal nerve transection group and OVX group were lower than inthe model group (P <0.05); The pathological changes of breast tissue were observed.Compared with the model group, the layers of the ductal epithelial cells, the lobularacinar of mammary gland，the acinar cavity and the dilation of breast ductal in both intercostal nerve transection group and OVX group were markedly reduced (P <0.05).In addition, the mRNA and protein levels of estradiol receptor and progestogenreceptor in breast tissue in both intercostal nerve transection group and OVX groupwere lower than the model group (P <0.05).Conclusion1. Cutting off the intercostal nerve could reduce the rat mammary glandhyperplasia of the breast tissue pathological changes.2. Cutting off the intercostal nerve could reduce expression of estrogen receptorand progesterone receptor in the rat mammary gland hyperplasia in breast tissue.3. Cutting off the intercostal nerve may be a new avenue for the treatment ofbreast hyperplasia.