【摘要】：目的觀察中介素(IMD)對大鼠缺血再灌注室性心律失常、縫隙連接蛋白43(Cx43)蛋白表達(dá)和磷酸化狀態(tài)的影響,探討其可能的機(jī)制。方法清潔級健康成年雄性Sprague-Dawley(SD)大鼠40只,隨機(jī)分為4組,每組10只:(1)假手術(shù)組,只在冠狀動脈左前降支(LAD)下方穿線,不結(jié)扎;(2)缺血再灌注組,結(jié)扎LAD缺血30min再灌注120 min;(3)IMD組,于缺血前15 min經(jīng)尾靜脈注射IMD(20nmol/kg),結(jié)扎LAD缺血30min再灌注120min;(4)Chelerythrine Chloride(CHE)組,于缺血前15min經(jīng)尾靜脈注射IMD(20nmol/kg)和蛋白激酶C(PKC)抑制劑CHE(20nmol/kg),結(jié)扎LAD缺血30 min再灌注120 min。監(jiān)測Ⅱ?qū)?lián)心電圖變化,記錄缺血再灌注全程的室性早搏(VPC)次數(shù)、室性心動過速(VT)總持續(xù)時間和心室顫動(VF)總持續(xù)時間,并進(jìn)行室性心律失常評分。采用H-E染色在光學(xué)顯微鏡下觀察心肌組織病理損傷情況。應(yīng)用Western印跡法分析心室肌Cx43蛋白表達(dá)及其磷酸化水平。結(jié)果缺血再灌注組大鼠在缺血和再灌注期間,VPC次數(shù)顯著多于假手術(shù)組(P0.05),VT和VF總持續(xù)時間均顯著長于假手術(shù)組(P值均0.05),室性心律失常評分顯著高于假手術(shù)組(P0.05)。IMD組大鼠VF和VT總持續(xù)時間均顯著短于缺血再灌注組(P值均0.05),室性心律失常評分顯著低于缺血再灌注組(P0.05),VPC次數(shù)與缺血再灌注組的差異無統(tǒng)計學(xué)意義(P=0.067)。CHE組大鼠的VT和VF總持續(xù)時間均顯著長于IMD組(P值均0.05),室性心律失常評分顯著高于IMD組(P0.05),VPC次數(shù)與IMD組的差異無統(tǒng)計學(xué)意義(P=0.219)。CHE組室性心律失常各項指標(biāo)與缺血再灌注組的差異均無統(tǒng)計學(xué)意義(P值均0.05)。心肌H-E染色光學(xué)顯微鏡下可見,假手術(shù)組心肌細(xì)胞排列整齊,心肌纖維完整,染色均勻,無變性、壞死等改變;缺血再灌注組心肌細(xì)胞體積增大,細(xì)胞間質(zhì)腫脹嚴(yán)重,心肌纖維不規(guī)則排列,出現(xiàn)大面積纖維斷裂、壞死,可見收縮帶形成,并有中性粒細(xì)胞浸潤;IMD組和CHE組與缺血再灌注組相比,組織形態(tài)得到明顯改善,細(xì)胞間質(zhì)腫脹顯著減輕,心肌纖維排列相對規(guī)則,有少量中性粒細(xì)胞浸潤。Western印跡法結(jié)果顯示,缺血再灌注組的兔抗磷酸化Cx43抗體(p-Cx43)蛋白相對表達(dá)量顯著低于假手術(shù)組(P0.05);IMD組的p-Cx43蛋白相對表達(dá)量顯著高于缺血再灌注組(P0.05);CHE組的pCx43蛋白相對表達(dá)量與缺血再灌注組的差異無統(tǒng)計學(xué)意義(P0.05),但顯著低于IMD組(P0.05)。缺血再灌注組的小鼠抗去磷酸化Cx43抗體(Np-Cx43)蛋白相對表達(dá)量顯著高于假手術(shù)組(P0.05);IMD組的Np-Cx43蛋白相對表達(dá)量顯著低于缺血再灌注組(P0.05);CHE組的Np-Cx43蛋白相對表達(dá)量顯著高于IMD組(P0.05),與缺血再灌注組的差異無統(tǒng)計學(xué)意義(P0.05)。結(jié)論 IMD可通過活化PKC信號通路,調(diào)節(jié)Cx43蛋白磷酸化狀態(tài),發(fā)揮抗缺血和再灌注室性心律失常的作用。
[Abstract]:Objective to investigate the effects of (IMD) on the expression and phosphorylation of gap junction protein 43 (Cx43) in rats with ventricular arrhythmias after ischemia-reperfusion. Methods Forty clean grade healthy adult male Sprague-Dawley (SD) rats were randomly divided into 4 groups: (1) sham-operated group, with no ligation under the left anterior descending coronary artery (LAD), (2) ischemia reperfusion group, LAD ischemic 30min reperfusion 120 min; (3) IMD group. IMD (20nmol/kg) was injected via caudal vein 15 min before ischemia, and LAD ischemia 30min was ligated for 120min. (4) in) Chelerythrine Chloride (CHE) group, IMD (20nmol/kg) and C (PKC) inhibitor CHE (20nmol/kg) were injected via caudal vein before ischemia, and LAD ischemia 30 min reperfusion 120 min. was ligated. The changes of lead 鈪，

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