The aim of this experiment was to investigate the effects of daidzein(DZ)on mammary gland development in mice during pregnancy.A total of 36 pregnant mice were randomly divided into a control group(treated with sterile PBS),a DZ group(DZ working fluid by intraperitoneal injection)and a E2 group(E2 working fluid by intraperitoneal injection),once daily,for 7 days.Af-ter normal delivery of pregnant mice,6 mice were selected from each group on the 1st and 10th day of the lactation period,then executed after blood sampling,and all mammary gland tissue were taken for the following experiments:1)mammary gland tissue was weighted and the mammary gland index was calculated;preparation of mammary gland tissue sections,HE staining;2)ELISA of estradiol,prolactin and insulin-like growth factor concentrations in serum;3)Western blot and RT-qPCR were used to analyze the expression of cell cyclin proteins and ER-a,ER-β proteins and genes in mammary gland tissues.The results showed that:compared with control group,DZ signif-icantly increased the area ratio of acinar in the mammary gland of mice(P＜0.05),decreased the area ratio of adipose tissue and increased proliferative expansion of adenohypophysis;DZ highly significantly increased serum PRL levels(P＜0.01)and serum IGF-1 content,reduced serum E2 levels;DZ significantly up-regulated the expression of CyclinD1,CyclinD3,PCNA and ER-β pro-teins(P＜0.05),and the mRNA level of ER-β gene was significantly up-regulate(P＜0.01).In conclusion,DZ can promote cell proliferation and division by increasing the expression of cell cycle proteins and proliferation proteins,promotes the proliferation of mammary gland follicles and in-creases mammary gland weight during pregnancy in mice,and at the same time increase the serum levels of IGF-1 and PRL in the female rats,which jointly promote the development of the mamma-ry glands during lactation.

The aim of this experiment was to investigate the effects of daidzein(DZ)on mammary gland development in mice during pregnancy.A total of 36 pregnant mice were randomly divided into a control group(treated with sterile PBS),a DZ group(DZ working fluid by intraperitoneal injection)and a E2 group(E2 working fluid by intraperitoneal injection),once daily,for 7 days.Af-ter normal delivery of pregnant mice,6 mice were selected from each group on the 1st and 10th day of the lactation period,then executed after blood sampling,and all mammary gland tissue were taken for the following experiments:1)mammary gland tissue was weighted and the mammary gland index was calculated;preparation of mammary gland tissue sections,HE staining;2)ELISA of estradiol,prolactin and insulin-like growth factor concentrations in serum;3)Western blot and RT-qPCR were used to analyze the expression of cell cyclin proteins and ER-a,ER-β proteins and genes in mammary gland tissues.The results showed that:compared with control group,DZ signif-icantly increased the area ratio of acinar in the mammary gland of mice(P＜0.05),decreased the area ratio of adipose tissue and increased proliferative expansion of adenohypophysis;DZ highly significantly increased serum PRL levels(P＜0.01)and serum IGF-1 content,reduced serum E2 levels;DZ significantly up-regulated the expression of CyclinD1,CyclinD3,PCNA and ER-β pro-teins(P＜0.05),and the mRNA level of ER-β gene was significantly up-regulate(P＜0.01).In conclusion,DZ can promote cell proliferation and division by increasing the expression of cell cycle proteins and proliferation proteins,promotes the proliferation of mammary gland follicles and in-creases mammary gland weight during pregnancy in mice,and at the same time increase the serum levels of IGF-1 and PRL in the female rats,which jointly promote the development of the mamma-ry glands during lactation.