Objective: To investigate the estrogenic effect of the incompatibility of Veratri Nigri Radix(VN) and Paeoniae Radix Alba(PRA) on immature mouse

so as to provide a scientific basis for eighteen incompatible medicaments VN and PRA. Method: One hundred female Kunming mice were randomly divided into 10 groups:the normal group

the PRA groups (4

2 g·kg-1)

estrogen receptor agonist group (E2

0.1 g·kg-1)

PRA+VN groups (PRA 4

2 g·kg-1+VN 0.045 g·kg-1)

E2 and VN group(E2 0.1 g·kg-1+VN 0.045 g·kg-1)

PRA+estrogen receptor antagonist(ICI 182780) groups (PRA 4

2 g·kg-1+ICI 0.005 g·kg-1)

E2 group (0.1 g·kg-1) and ICI group (E2 0.1 g·kg-1+ICI 0.005 g·kg-1). Six days later

the immature mouse uterus coefficient was calculated. E2

LH and FSH were detected. Uterus and vagina pathological changs were observed by HE staining. Result: Compared with normal group

PRA and E2 groups showed significantly increase in the uterus index (P<0.01) and the level of E2 (P<0.05)

decrease in the level of LH(P<0.01) and FSH(P<0.01)

and the growth and development of uterus and vagina of the immature mouse

with a slightly weaker effect to E2. in the PRA plus VN group

uterus index decreased (P<0.01)

level of E2 notably decreased(P<0.01)

level of LH (P<0.01) and FSH (P<0.01)increased

and the growth and development of uterus and vagina decreased

with the same effect to PRA plus ICI. Conclusion: These findings prove that PRA exerts estrogenic effect

VN has the anti-estrogen effect and can antagonize the estrogenic efficacy of PRA.