[摘要] 目的 研究δ阿片受體激動劑DADLE(D-Ala2-D-Leu5-enkephalin)對膿毒癥大鼠肺組織高遷移率族蛋白1(HMGB1)的水平的影響。方法 將96只SD大鼠分為假手術(shù)組(SO)、膿毒癥組(SEP)、DADLE組[制模后立即給藥DADLE(5mg/kg,腹腔內(nèi)注)],每組32只。采用改良盲腸結(jié)扎穿孔方法(CLP)建立大鼠膿毒癥模型,于制模后6h、12h、18h和24h每組各取8只處死取材,Western Blot法檢測肺組織HMGB1水平。結(jié)果 12h時SEP組和DADLE組HMGB1水平與SO組相比均明顯升高(P<0.05),且DADLE組明顯低于SEP組(P<0.05);18h時,SEP組和DADLE組HMGB1水平達到最高,同樣,DADLE組明顯低于SEP組(P<0.05);24h時SEP組和DADLE組HMGB1水平較18h有所降低,但DADLE組仍明顯低于SEP組(P<0.05)。結(jié)論 DADLE能明顯降低膿毒癥大鼠肺組織HMGB1水平。
[關(guān)鍵詞] DADLE;膿毒癥;高遷移率族蛋白1
[中圖分類號] R631 [文獻標(biāo)識碼] B [文章編號] 1673-9701(2011)34-08-02
Effect of Delta-opioid Receptor Agonist on Lung Tissue HMGB1 Level in A Rat Model with Sepsis
TAO Yulong TANG Chengwu FENG Wenming BAO Ying ZHU Ming
Molecular Surgery Institute,Department of Hepatobiliary Surgery and Molecular Surgery,the First People's Hospital Affiliated to Huzhou University Medical College,Huzhou 313000,China
[Abstract] Objective To study the effect of delta-opioid receptor agonist(DADLE)on lung tissue HMGB1 level in rat with sepsis. Methods Ninty-six SD rats were randomly divided into sham operated group(SO),septic group(SEP)and DADLE group(DADLE). Septic model was produced by cecal ligation and puncture(CLP). In SO group,the abdomen was opened without any other treatment. In DADLE group,DADLE was administrated at a dose of 5mL/kg by intra-peritoneal injection after CLP. Rats were sacrificed at 6h,12h,18h and 24h after CLP. Lung tissue HMGB1 level was determined by Western Blot. Results Lung tissue HMGB1 levels of SEP and DADLE group began to increase at 12h and reached the peak around 18h after CLP. Notably,lung tissue HMGB1 levels of DADLE group at 12h,18h and 24h were significantly lower than those of SEP group(P<0.05). Conclusion DADLE could significantly decrease lung tissue HMGB1 level in a rat model of sepsis.
[Key words] DADLE;Sepsis;High-mobility group box 1 protein
膿毒癥是嚴(yán)重感染、創(chuàng)傷及大手術(shù)等應(yīng)激狀況時常見的并發(fā)癥,已經(jīng)成為當(dāng)今重癥監(jiān)護室的首要死亡原因[1]。膿毒癥時多種炎癥因子參與了膿毒癥的病理過程,高遷移率族蛋白B1(high mobility group box 1 protein,HMGB1)作為潛在晚期炎性因子,是膿毒癥致死效應(yīng)的重要炎性介質(zhì),是致急性肺損傷(ALI)的一種重要的細胞因子[2],干預(yù)HMGB1可有效防止ALI和ARDS的發(fā)生與發(fā)展[3-5]。δ阿片受體激動劑DADLE(D-Ala2-D-Leu5-enkephalin)是一種人工合成的非選擇性δ阿片受體激動劑,我們以往的研究發(fā)現(xiàn)DADLE能明顯減輕膿毒癥大鼠肺組織損傷[6]并改善死亡率[7]。本研究旨在探討其對膿毒癥大鼠肺組織HMGB1水平的影響,從而對DADLE在膿毒癥中對肺組織的保護作用進行初步闡述。
1 材料與方法
1.1 實驗材料
DADLE(D-Ala2-D-Leu5-enkephalin)分子式C29H39N507,購自美國Sigma公司。
1.2 動物分組及膿毒癥模型建立
清潔級健康SD雄性大鼠96只,體重270~320g購于上海斯萊克實驗動物有限責(zé)任公司,隨機分為DADLE組、假手術(shù)組(SO組)和膿毒癥組(SEP組),每組32只,以改良的盲腸結(jié)扎穿孔法(CLP)[8]建立膿毒癥大鼠模型。假手術(shù)組除不施行CLP,其余操作同SEP組;DADLE組在模型建立后立即腹腔注射濃度為0.5mg/mL的DADLE(劑量:5mL/kg體重)。CLP后6h、12h、18h和24h每組斷頸處死8只大鼠。
1.3 肺組織HMGB1蛋白水平檢測
將肺組織蛋白轉(zhuǎn)膜后在封閉液中與兔抗HMGB1多克隆抗體(一抗,購自美國BD Pharmingen公司)結(jié)合,然后與辣根過氧化物酶標(biāo)記的山羊抗兔IgG(二抗,購自北京中山生物技術(shù)有限公司)室溫孵育。采用化學(xué)發(fā)光反應(yīng)試劑盒進行發(fā)光,底片暗室曝光后經(jīng)LEICA Q-5501W圖像分析系統(tǒng)(德國Leica公司)處理,對各條帶的吸光度值進行定量分析。
1.4 統(tǒng)計學(xué)處理
采用SPSS10.0軟件處理。計量資料用(χ±s)表示,多組間比較用方差分析,組間兩兩比較采用q檢驗。P<0.05為差異有統(tǒng)計學(xué)意義。
2 結(jié)果
CLP后6h SEP和DADLE組肺組織HMGB1水平開始升高,但三組間無明顯差異(P>0.05);12h時SEP組和DADLE組HMGB1水平與SO組相比均明顯升高(P<0.05),且DADLE組明顯低于SEP組(P<0.05);18h時SEP組和DADLE組HMGB1水平達到最高。同樣,DADLE組明顯低于SEP組(P<0.05);24h時SEP組和DADLE組HMGB1水平較18h有所降低,但DADLE組仍明顯低于SEP組(P<0.05)。見表1。
3 討論
膿毒癥時細菌產(chǎn)生內(nèi)毒素導(dǎo)致大量炎癥因子釋放,包括早期炎癥因子(如TNF-α和IL-1β)和晚期炎癥因子(如HMGB1),正是這些炎癥因子導(dǎo)致了器官組織的損傷[9,10]。然而,一些針對早期炎癥因子的治療在臨床上并未收到良好的療效,因為早期炎癥因子在炎癥發(fā)展的早期階段就已經(jīng)開始釋放,并未給拮抗治療留下足夠的時間窗。況且,在全身炎癥反應(yīng)啟動之后再使用TNF-α和IL-1β的抑制劑也無法取得明顯的療效[11-13]。有學(xué)者發(fā)現(xiàn),使用抗HMGB1抗體能明顯減少膿毒癥小鼠的死亡率,即使是在膿毒癥發(fā)生24h之后仍有明顯的保護作用[14],這意味著針對HMGB1的治療策略具有良好的時間窗。因此,HMGB1可能是治療膿毒癥的新靶點。本研究中DADLE組肺組織HMGB1水平在12h、18h和24h均明顯低于SEP組,表明DADLE能明顯抑制肺組織HMGB1的表達,減輕急性肺損傷,從而對膿毒癥大鼠起到一定的保護作用。
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(收稿日期:2011-08-01)