劉 劍,吳明昊,山秀杰,張 蕊,高 宇,胡桂才
(1.承德醫(yī)學(xué)院,河北承德 067000;2.承德醫(yī)學(xué)院附屬醫(yī)院)
基礎(chǔ)醫(yī)學(xué)
利拉魯肽對(duì)肥胖大鼠腎臟脂質(zhì)沉積的影響
劉劍1,吳明昊1,山秀杰1,張蕊1,高宇2△,胡桂才2
(1.承德醫(yī)學(xué)院,河北承德 067000;2.承德醫(yī)學(xué)院附屬醫(yī)院)
目的:研究利拉魯肽對(duì)肥胖大鼠腎臟脂質(zhì)沉積的影響。方法:32只雄性Wistar大鼠隨機(jī)分為普食組、肥胖組、利拉魯肽干預(yù)1組和利拉魯肽干預(yù)2組,每組8只大鼠。采用高脂飲食制作肥胖大鼠模型,以體重高于普食組20%作為肥胖成模標(biāo)準(zhǔn),利拉魯肽干預(yù)1組和利拉魯肽干預(yù)2組分別給予不同劑量利拉魯肽干預(yù)2周。分別檢測(cè)4組大鼠的24小時(shí)尿蛋白(MAU),血肌酐(Scr)、尿素氮(BUN)和游離脂肪酸(FFA)的含量,以及腎臟甘油三酯(TG)和甘油二酯(DAG)的含量。結(jié)果:與普食組比較,肥胖組大鼠MAU、Scr、BUN、FFA、TG、DAG均明顯升高(P<0.01);與肥胖組比較,干預(yù)2組大鼠的MAU、Scr、BUN、FFA、TG、DAG明顯降低(P<0.01,P<0.05),而干預(yù)1組大鼠僅MAU、FFA明顯降低(P<0.05);與干預(yù)1組比較,干預(yù)2組大鼠的MAU、FFA、TG、DAG明顯降低(P<0.05)。結(jié)論:利拉魯肽可能通過(guò)減輕腎臟脂質(zhì)沉積改善肥胖相關(guān)性腎臟損傷。
利拉魯肽;肥胖;腎臟;脂質(zhì)沉積
據(jù)統(tǒng)計(jì),目前全球成人中有23億人超重,7億人達(dá)到肥胖水平[1]。肥胖率的不斷攀升,給公眾健康造成巨大隱患。越來(lái)越多的證據(jù)表明,腎臟脂質(zhì)堆積是肥胖所致腎損傷的原因之一[2]。利拉魯肽是一種新型降糖藥和減肥藥,有研究發(fā)現(xiàn)其對(duì)肥胖大鼠腎臟具有保護(hù)作用,但作用機(jī)制尚不明確。本研究應(yīng)用利拉魯肽對(duì)高脂誘導(dǎo)肥胖大鼠進(jìn)行干預(yù),探討利拉魯肽阻斷肥胖所致腎損傷的可能機(jī)制。
1.1動(dòng)物模型的建立與分組 雄性Wistar大鼠32只,體重180-220g。隨機(jī)選取其中的8只作為普食組,普通飼料喂養(yǎng)8周;另24只大鼠高脂飼料喂養(yǎng)8周,以體重高于普食組20%作為肥胖成模標(biāo)準(zhǔn)[3],成模肥胖大鼠再隨機(jī)分為肥胖組、利拉魯肽干預(yù)1組和利拉魯肽干預(yù)2組,每組8只大鼠。后普食組大鼠繼續(xù)普食喂養(yǎng)2周,同時(shí)給予100μg/ kg/d生理鹽水腹部皮下注射;肥胖組、利拉魯肽干預(yù)1組和利拉魯肽干預(yù)2組大鼠繼續(xù)高脂飼料喂養(yǎng)2周,同時(shí)分別給予100μg/kg/d生理鹽水、100μg/kg/d利拉魯肽、200μg/kg/d利拉魯肽腹部皮下注射。
1.2指標(biāo)檢測(cè)
1.2.124h尿微量白蛋白(MAU):藥物干預(yù)2周后,應(yīng)用代謝籠收集各組大鼠24h尿液,免疫比濁法測(cè)定各組大鼠的MAU。
1.2.2血液指標(biāo):大鼠麻醉后處死,經(jīng)腹主動(dòng)脈取血,離心取血清,-80℃冰箱保存。采用全自動(dòng)生化分析儀(日立7600)檢測(cè)血肌酐(Scr)和尿素氮(BUN)的含量;銅試劑比色法檢測(cè)血清游離脂肪酸(FFA)的含量(試劑盒購(gòu)自南京建成生物工程公司)。
1.2.3腎臟指標(biāo):取大鼠腎臟勻漿,采用GPO-PAP法檢測(cè)甘油三酯(TG,試劑盒購(gòu)自南京建成生物工程公司)的含量,采用ELISA法檢測(cè)甘油二酯(DAG,試劑盒購(gòu)自上海酶聯(lián)生物科技有限公司)的含量。
與普食組比較,肥胖組大鼠的MAU、Scr、BUN、FFA和腎臟TG和DAG的含量均顯著升高,差異有統(tǒng)計(jì)學(xué)意義(P<0.01)。與肥胖組比較,干預(yù)1組大鼠僅MAU、FFA明顯降低(P<0.05);與肥胖組比較,干預(yù)2組大鼠的MAU、BUN、Scr、FFA、TG、DAG均明顯下降(P<0.01,P<0.05)。與干預(yù)1組比較,干預(yù)2組大鼠的MAU、FFA、TG、DAG明顯降低,組間比較差異有統(tǒng)計(jì)學(xué)意義(P<0.05)。見(jiàn)附表:
附表 四組大鼠各指標(biāo)檢測(cè)結(jié)果(n=8)
肥胖癥與慢性腎臟?。–KD)的發(fā)病率增加呈平行關(guān)系,流行病學(xué)研究顯示,肥胖是CKD的獨(dú)立危險(xiǎn)因素[4]。久坐不動(dòng)的生活方式以及高能量食物不斷進(jìn)入日常飲食中,造成人體能量攝入過(guò)多誘發(fā)體重增加,導(dǎo)致肥胖癥的發(fā)病率不斷攀升。近幾年研究表明,腎臟異位脂質(zhì)沉積可能是肥胖相關(guān)性腎損傷的原因之一。本次研究亦發(fā)現(xiàn),高脂誘導(dǎo)的肥胖大鼠,腎功能下降、MAU升高;同時(shí),肥胖組大鼠腎臟的TG和DAG含量明顯上升,表明腎臟異位脂質(zhì)沉積可能參與了肥胖相關(guān)性腎損傷的發(fā)病過(guò)程。
通常攝入過(guò)剩的能量由白色脂肪組織以TG形式儲(chǔ)存起來(lái),當(dāng)能量攝入超過(guò)白色脂肪組織的存儲(chǔ)容量時(shí),就會(huì)導(dǎo)致異位脂質(zhì)堆積,可沉積在肝、骨骼肌、胰腺、腎臟等部位[5]。TG本身無(wú)脂毒性,但可導(dǎo)致FFA的蓄積,F(xiàn)FA通過(guò)其中間代謝產(chǎn)物,如脂肪酰輔酶A(FA-CoA)、甘油二脂(DAG)、神經(jīng)酰胺等對(duì)沉積部位造成脂毒性損害[6]。脂毒性對(duì)腎臟的損傷機(jī)制包括活性氧的大量產(chǎn)生、細(xì)胞內(nèi)信號(hào)轉(zhuǎn)導(dǎo)通路的破壞、炎癥和纖維化因子的釋放、脂質(zhì)誘導(dǎo)的細(xì)胞凋亡等[7-8]。
利拉魯肽是一種較新的降糖藥與減肥藥,因其廣泛獨(dú)特的胰外效應(yīng),在臨床應(yīng)用中備受關(guān)注。利拉魯肽對(duì)肥胖患者和糖尿病腎病患者的腎臟保護(hù)作用已得到證實(shí),但具體機(jī)制尚不明了。本研究發(fā)現(xiàn),經(jīng)高劑量利拉魯肽干預(yù)后,肥胖大鼠的腎功能、尿蛋白明顯得到改善,且效果優(yōu)于低劑量利拉魯肽組。本研究表明,利拉魯肽對(duì)肥胖大鼠的腎臟具有保護(hù)作用,且效應(yīng)呈濃度依賴性。本研究同時(shí)還發(fā)現(xiàn),經(jīng)藥物干預(yù)后,肥胖大鼠腎臟TG、DAG的含量明顯下降,提示利拉魯肽可能通過(guò)減少腎臟脂質(zhì)沉積,進(jìn)而改善肥胖相關(guān)性腎臟損傷。因此,本研究可為利拉魯肽在肥胖相關(guān)性腎病的臨床治療上提供新的思考領(lǐng)域。
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EFFECTS OF LIRAGLUTIDE ON RENAL LIPID DEPOSITION OF OBESE RATS
LIU Jian, WU Ming-hao, SHAN Xiu-jie, et al
(Chengde Medical College, Hebei Chengde 067000, China)
Objective: To study the effects of liraglutide on renal lipid deposition of obese rats. Methods: 32 male Wistar rats were randomly divided into the following 4 groups with 8 rats in each group: normal diet gr oup, obese group,liraglutide intervention group 1 and liraglutide intervention group 2. The obese rats were established by using fat diet and the standard for successful model was rats' body weight increasing 20%. Then the rats in liraglutide intervention group 1 and liraglutide intervention group 2 were given liraglutide in different dose for 2 weeks. The 24-hour proteinuria (MAU),creatinine (Scr) ,urea nitrogen (BUN) and free fatty acid (FFA) content in serum, as well as triglyceride (TG), diglyceride(DAG) content in kidney of rats in each group were detected. Results: Compared with rats in normal diet group, the MAU,Scr, BUN, FFA, TG and DAG of rats in obese group increased obviously (P<0.05). Compared with rats in obese group, the MAU, Scr, BUN, FFA, TG and DAG of rats in liraglutide intervention group 2 decreased obviously (P<0.01,P<0.05); only the MAU and FFA of rats in liraglutide intervention group 1 decreased obviously (P<0.05). Compared with rats in liraglutide intervention group 1, the MAU, FFA, TG and DAG of rats in liraglutide intervention group 2 decreased obviously (P<0.05). Conclusions: Liraglutide can improve obesity related renal injury by alleviating renal lipid deposition.
Liraglutide; Obesity; Kidney; Lipid deposition
R965
A
1004-6879(2016)01-001-03
2015-08-26)