Objective: To carry out a morphological study on the protective effect of Tamoxifen combined with Pisuxiao in rats of mammary gland hyperplasia. Method: Rat were randomized into 7 groups:nomal

model

Tamoxifen(Tam) with Pisuxiao(PSX

3.0

1.5

0.75 g·kg-1)and Tamoxifen (1.67 mg·kg-1)

Pisuxiao (2.5 g·kg-1)

and ig for 45 days.Rat models of of mammary glands hyperplasia were established by intramuscular injection of estradiol benzoate (E2)and progesterone(P). Pathologic histopathology of the breast tissue was check up under the microscope.The estradiol and progesterone contents were determined.Estrogen receptor (ER) and progesterone receptor (PR) were evaluated by immunohistochemical technique. Result: In compare with model groups

the estradiol level of Tam with PSX group was evidently lower than that in the model group

Tamoxifen with Pisuxiao could inhibit the ductal and lobular hyperplasia and induce hyperplasia(P<0.01 or P<0.05)

reduce the content of E2 and P in serum (P<0.01).At the sametime ER and PR expressionwere obviously inhibited(P<0.01 or P<0.05). Conclusion: Tamoxifen combined with Pisuxiao is protective in rats withexperimental mammary glands hyperplasia.