| Objectivep27kip1 is one of important number of CDI. protein family that can associate with cyclin - cdk complexes. These yesrs people find that 17β - estradiol( E2) can regulation the protein. Cell growth is corrected through ability of p27kip1 to inhibit progression through the G1 phase of the cell cycle. In this study . Our aim was to investigate expression of p27kip1 in the progesterone - induced antiprolif-eration in vein grafting model. The result may have application to the treatment of vascular proliferative disease.MethodsAutogenous vein graft model was established in 84 Female SD rats by transplanting internal branch of jugular vein to carotid artery by end to end anastomosis. After anesthetizing with 10% chloral hydrate (2ml/kg) , using mediam incision in cervical part , cutting skin , freeing jugular vein and common carotid artery ,cutting jugular vein 0.5cm ,washing with heparin saline, using 11 -0 no - injure suturing , end -to - end anastomosis jugular vein into common carotid artery . Female SD rats were randomly divided into 3 groups; control group, ovariectomized group, and E2 + ovariectomized groups. Dosis is 20μg/kg everyday, and hypodermic injection. The grafted veins were harvested at 3 day , 1 week ,2 week and 4 week respectively after the operation. IH (intimal hyperplasia) , Verhoeff ,PCNA ,p27kip1 were observed with pathology and immuno-histochemistry and analyzed by computer digitizing system. Western blot detect the express of p27kip1 in every period .ResultThere was a significant decrease in the intimal average thickness at 7 d, 14 d and 28 d (p <0.05) in the E2 group. But there was a significant increase in the ovariectomized groups compared with control groups . Immunohistochemical analysis of PCNA indicated the decreased positive cell in the E2 group compared with the control groups at 1 week and 2 week ( p < 0.05 ). There was a significant increase in the ovariectomized groups compared with control groups (p<0. 05 ).. Immunohistochemical analysis of p27kip1 indicated the increased positive cell in the E2 groups (p <0.05). The peak at 14 days. There was a significant decreased in the ovariectomized groups compared with control groups . The tendency of Western blot is similar to the expression of p27kip1 proteinDiscussionIn humans , the epidemiological studies shows that premenopausal women have a much lower mortality bora, atherosckerotic cardiovascular disease than, suggesting that sex hormones might have a cardioprotective effect. This hypothesis was supported by the evidence that estrogen replacement reduces the incidence of cardiovascular diseases in postmenopausal women. In recently year's studies show the mechanisms of the cardioprotective effect of estrogen is relevant to the cell cycle. It is well established that cyclins play a positive role in promoting cell cycle transitions via their ability to associate with and activate their cog-nae cyclin - dependent kinates( Cdks). p27kip1 is one of important number of CDI protein family that can associate with cyclin - cdk complexes. p27kip1 is a nonspecific CKI, can inhibit different CDK compounds. It can inhibit progression through the G1 phase of the cell cycle. In this study we have analyzed that the role p27kip1cyclin -dependent kinase inhibitor on vascular cell growth in vivo. Compared with the control groups E2 group have a increased expression of p27kip1 and have a decreased in PCNA. Ovariectomized groups have a contrary tendency. This experiment results show that estradiol can induce the expression... |
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