Effect Of Oestrogen On The Expression Of Rho-kinase In The Vaginal Smooth Muscle Cells Of Rats

Objective: To determine the expression of RhoA/Rho-kinasein the vaginal smooth muscle cells of castrated rats and the effect ofestrogen on the expression of RhoA/Rho-kinase. Methods:30female SDrats of10weeks were randomly divided into groups C4(4-week controlgroup),C6(6-week control group),OE4(4-week bilateralovariectomy),OE6(6-week bilateral ovariectomy),E4(4-week bilateralovariectomy and oestrogen replacement) and E6(6-week bilateralovariectomy and oestrogen replacement), Castrated and oestrogenreplacement after one week adaptive feeding, intraperitoneal anesthesiawith1%Pentobarbital, control group rats were carried out incision lowerabdomen without bilateral ovariectomy, the castrated group rats werecarried out bilateral ovariectomy for4and6weeks, while Group E4andE6were carried out bilateral ovariectomy and oestrogen replacement for4and6weeks, feeding in20℃-21℃, humidity50%-65%environment.Four and six weeks after operation, determined the serum E2level, theexpressions of Rock1and Rock2in vaginal smooth muscle cells byimmunohistochemistry staining, separately investigated the expressionsof Rock1and Rock2in vaginal smooth muscle cells by Western blot,(Marker: β-actin). Statistical Analysis：all datas were expressed as mean±standard error， statistical analysis was accomplished with SPSS17.0 software，the two groups using t test, P <0.05for the difference wassignificant. Results: After Four and six weeks,Serum estradiol wassignificantly lower in group OE4and OE6than in groups C4and C6(P <0.01),After oestrogen replacement for4and6weeks,It had no significantdifference about serum estradiol between groups E4and E6. Rock1andRock2were expressed in the vaginal smooth muscle cells of the rats. Theprotein expression of Rock1was significantly more in groups OE4andOE6than in groups C4and C6(0.261±0.039vs0.207±0.032；0.270±0.037vs0.208±0.032，P＜0.05), and so were Rock2in groups OE4andOE6in comparison with groups C6and E6(0.377±0.035vs0.294±0.033；0.388±0.038vs0.300±0.034， P＜0.05). After oestrogenreplacement for4and6weeks, there was no difference between theexpressions of Rock1and Rock2. Conclusion: Rock1and Rock2weremainly expressed in cytoplasm of rat vaginal smooth muscle,Thereplacement of oestrogen may inhibits the expression of Rock1andRock2in the vaginal smooth muscle cells of the rats,E2may regulate thefunction of vaginal smooth muscle through regulate the expression ofRock1and Rock2.