Effects of genistein on oestrogen and progesterone receptor, proliferative marker Ki-67 and carbonic anhydrase localisation in the uterus and cervix of gilts after insemination

Soya products are routinely fed to domestic animals as an important source of protein. The aim of this work was to study how the phytooestrogen genistein, supplemented at a feed relevant level, affects the morphology and distribution of reproductive hormone receptors, proliferative activities and carbonic anhydrase (CA) in the uterus and cervix of gilts. Eleven gilts were fed a soya-free diet. Six were given genistein (1 mg/kg bw) twice daily for eight days starting three days before expected oestrus. Five gilts were used as controls. All gilts were inseminated (AI) one day after signs of standing oestrus and euthanized three days after AI. Samples from the uterus and cervix were processed for morphometric evaluation, immunohistochemical localisation of oestrogen receptors α and β (ERα and ERβ), progesterone receptor (PR), proliferative marker Ki-67 and histochemical localisation of CA. Nuclear staining for ERβ was detected in surface epithelial, glandular and some stromal cells in the uterus and in the cervix surface epithelial cells. ERα and PR were observed in surface epithelium, subepithelial stromal cells and smooth muscle cells of uterus and cervix, and glandular cells of the uterus. Ki-67 positive cells were recorded in uterine and cervical surface epithelium and subepithelial stromal layer. CA was mainly confined to glandular cells of the uterus. Immunohistochemical results were evaluated using semi-quantitative image analysis. Statistic comparison between groups revealed no differences. However, intra-treatment evaluation and correlations indicate that the supplementation of genistein modulates the expression pattern of all receptors and Ki-67, which may induce cellular activities in both the uterus and cervix of early pregnant gilts.