中华心血管病杂志
中華心血管病雜誌
중화심혈관병잡지
Chinese Journal of Cardiology
2011年
8期
711-716
,共6页
赵鹏%张洁%褚熙%苑海涛%崔连群%朱兴雷
趙鵬%張潔%褚熙%苑海濤%崔連群%硃興雷
조붕%장길%저희%원해도%최련군%주흥뢰
心室功能,左%败血症%金属硫蛋白%氧化应激
心室功能,左%敗血癥%金屬硫蛋白%氧化應激
심실공능,좌%패혈증%금속류단백%양화응격
Ventricular function,left%Sepsis%Metallothionein%Oxidative stress
目的 探讨抗氧化剂金属硫蛋白(metallothionein,MT)对败血症小鼠心功能不全的保护作用及其抗氧化应激作用.方法 将年龄与体重配对的雄性FVB小鼠与心脏特异性过表达MT小鼠分为四组:FVB小鼠对照组(FVB组),FVB小鼠脂多糖(Lipopolysaccharide,LPS)处理组(FVB-LPS组),MT转基因小鼠对照组(MT组)和MT小鼠LPS处理组(MT-LPS组).LPS处理组小鼠腹腔注射LPS,剂量为4 mg/kg.6 h后应用心脏超声及单心肌细胞机械功能测定技术测定小鼠心脏整体功能及单个细胞收缩舒张功能.M型超声心动图测定心率、左心室舒张末期及左心室收缩末期内径(LVEDD、LVESD),计算左心室射血分数(EF)及左心室短轴缩短率(FS),细胞收缩和舒张通过收缩峰值、最大收缩和舒张速率积分(±dl/dt)、到达收缩峰值的时间、90%舒张时间进行评估.细胞内Ca2+浓度的变化通过在360/380两个波长下fura-2荧光强度比来推断,细胞内Ca2+的清除率用荧光延迟时间来衡量,如适合程序的单指数曲线或双指数曲线.通过对细胞内活性氧含量测定和谷胱甘肽/氧化型谷胱甘肽比率的测定来观察MT抗氧化应激作用.结果 心脏超声结果表明,与自身对照相比,腹腔注射LPS后小鼠心率增快及LVESD增加(P＜0.05).但LVEDD、EF及FS明显减小(P＜0.05),MT-LPS组小鼠心脏功能较FVB-LPS组有明显改善:心率、LVEDD、EF、FS比分别为(528±72)次/min与(557±69)次/min、(2.7±0.7)mm与(2.3±0.6)mm、(66±14)%与(42±10)%、(46±11)%与(30±10)%,P＜0.05.FVB-LPS组小鼠单个心肌细胞收缩峰值及±dl/dt均较MT-LPS组降低[(5±1.1)%与(7.2±0.8)%,(160±15)μm/s与(212±36)μm/s,(175±32)μm/s与(208±29)μm/s]并且90%舒张时间延长[(0.24±0.03)s与(0.19±0.02)s,P＜0.05].细胞内Ca2+浓度的变化及Ca2+的清除率的变化规律也同上述,心脏特异性过表达MT可改善由LPS诱导的单心肌细胞收缩、舒张功能不全与细胞内Ca2+处理能力的减低.心脏特异性过表达MT减轻了细胞内活性氧的含量[(0.35±0.08)A值/μg蛋白与(0.24±0.03)A值/μg蛋白,P＜0.05],提高了谷胱甘肽/氧化型谷胱甘肽的比率(2.1±0.2与2.6±0.4,P＜0.05).结论 研究表明,心脏特异性过表达MT改善了LPS引起的心脏收缩、舒张功能障碍,维持了胞内Ca2+的稳态和减轻了氧化应激,可以改善败血症引起的小鼠心功能不全.
目的 探討抗氧化劑金屬硫蛋白(metallothionein,MT)對敗血癥小鼠心功能不全的保護作用及其抗氧化應激作用.方法 將年齡與體重配對的雄性FVB小鼠與心髒特異性過錶達MT小鼠分為四組:FVB小鼠對照組(FVB組),FVB小鼠脂多糖(Lipopolysaccharide,LPS)處理組(FVB-LPS組),MT轉基因小鼠對照組(MT組)和MT小鼠LPS處理組(MT-LPS組).LPS處理組小鼠腹腔註射LPS,劑量為4 mg/kg.6 h後應用心髒超聲及單心肌細胞機械功能測定技術測定小鼠心髒整體功能及單箇細胞收縮舒張功能.M型超聲心動圖測定心率、左心室舒張末期及左心室收縮末期內徑(LVEDD、LVESD),計算左心室射血分數(EF)及左心室短軸縮短率(FS),細胞收縮和舒張通過收縮峰值、最大收縮和舒張速率積分(±dl/dt)、到達收縮峰值的時間、90%舒張時間進行評估.細胞內Ca2+濃度的變化通過在360/380兩箇波長下fura-2熒光彊度比來推斷,細胞內Ca2+的清除率用熒光延遲時間來衡量,如適閤程序的單指數麯線或雙指數麯線.通過對細胞內活性氧含量測定和穀胱甘肽/氧化型穀胱甘肽比率的測定來觀察MT抗氧化應激作用.結果 心髒超聲結果錶明,與自身對照相比,腹腔註射LPS後小鼠心率增快及LVESD增加(P＜0.05).但LVEDD、EF及FS明顯減小(P＜0.05),MT-LPS組小鼠心髒功能較FVB-LPS組有明顯改善:心率、LVEDD、EF、FS比分彆為(528±72)次/min與(557±69)次/min、(2.7±0.7)mm與(2.3±0.6)mm、(66±14)%與(42±10)%、(46±11)%與(30±10)%,P＜0.05.FVB-LPS組小鼠單箇心肌細胞收縮峰值及±dl/dt均較MT-LPS組降低[(5±1.1)%與(7.2±0.8)%,(160±15)μm/s與(212±36)μm/s,(175±32)μm/s與(208±29)μm/s]併且90%舒張時間延長[(0.24±0.03)s與(0.19±0.02)s,P＜0.05].細胞內Ca2+濃度的變化及Ca2+的清除率的變化規律也同上述,心髒特異性過錶達MT可改善由LPS誘導的單心肌細胞收縮、舒張功能不全與細胞內Ca2+處理能力的減低.心髒特異性過錶達MT減輕瞭細胞內活性氧的含量[(0.35±0.08)A值/μg蛋白與(0.24±0.03)A值/μg蛋白,P＜0.05],提高瞭穀胱甘肽/氧化型穀胱甘肽的比率(2.1±0.2與2.6±0.4,P＜0.05).結論 研究錶明,心髒特異性過錶達MT改善瞭LPS引起的心髒收縮、舒張功能障礙,維持瞭胞內Ca2+的穩態和減輕瞭氧化應激,可以改善敗血癥引起的小鼠心功能不全.
목적 탐토항양화제금속류단백(metallothionein,MT)대패혈증소서심공능불전적보호작용급기항양화응격작용.방법 장년령여체중배대적웅성FVB소서여심장특이성과표체MT소서분위사조:FVB소서대조조(FVB조),FVB소서지다당(Lipopolysaccharide,LPS)처리조(FVB-LPS조),MT전기인소서대조조(MT조)화MT소서LPS처리조(MT-LPS조).LPS처리조소서복강주사LPS,제량위4 mg/kg.6 h후응용심장초성급단심기세포궤계공능측정기술측정소서심장정체공능급단개세포수축서장공능.M형초성심동도측정심솔、좌심실서장말기급좌심실수축말기내경(LVEDD、LVESD),계산좌심실사혈분수(EF)급좌심실단축축단솔(FS),세포수축화서장통과수축봉치、최대수축화서장속솔적분(±dl/dt)、도체수축봉치적시간、90%서장시간진행평고.세포내Ca2+농도적변화통과재360/380량개파장하fura-2형광강도비래추단,세포내Ca2+적청제솔용형광연지시간래형량,여괄합정서적단지수곡선혹쌍지수곡선.통과대세포내활성양함량측정화곡광감태/양화형곡광감태비솔적측정래관찰MT항양화응격작용.결과 심장초성결과표명,여자신대조상비,복강주사LPS후소서심솔증쾌급LVESD증가(P＜0.05).단LVEDD、EF급FS명현감소(P＜0.05),MT-LPS조소서심장공능교FVB-LPS조유명현개선:심솔、LVEDD、EF、FS비분별위(528±72)차/min여(557±69)차/min、(2.7±0.7)mm여(2.3±0.6)mm、(66±14)%여(42±10)%、(46±11)%여(30±10)%,P＜0.05.FVB-LPS조소서단개심기세포수축봉치급±dl/dt균교MT-LPS조강저[(5±1.1)%여(7.2±0.8)%,(160±15)μm/s여(212±36)μm/s,(175±32)μm/s여(208±29)μm/s]병차90%서장시간연장[(0.24±0.03)s여(0.19±0.02)s,P＜0.05].세포내Ca2+농도적변화급Ca2+적청제솔적변화규률야동상술,심장특이성과표체MT가개선유LPS유도적단심기세포수축、서장공능불전여세포내Ca2+처리능력적감저.심장특이성과표체MT감경료세포내활성양적함량[(0.35±0.08)A치/μg단백여(0.24±0.03)A치/μg단백,P＜0.05],제고료곡광감태/양화형곡광감태적비솔(2.1±0.2여2.6±0.4,P＜0.05).결론 연구표명,심장특이성과표체MT개선료LPS인기적심장수축、서장공능장애,유지료포내Ca2+적은태화감경료양화응격,가이개선패혈증인기적소서심공능불전.
Objective This study was designed to examine the impact of the antioxidant metallothionein (MT) on cardiac contractile, intracellular Ca2+ function and oxidative stress in lipopolysaccharide (LPS)-treated mice. Methods Weight and age matched adult male FVB and cardiacspecific MT-overexpressing transgenic mice were injected intraperitoneally with 4 mg/kg Escherichia Coli LPS dissolved in sterile saline or an equivalent volume of pathogen-free saline ( control groups). Six hours following LPS or saline injection, cardiac geometry and function were evaluated in anesthetized mice using the 2-D guided M-mode echocardiography. Mechanical and intracellular Ca2+ properties were examined in hearts. Cell shortening and relengthening were assessed using the following indices: peak shortening (PS)-indicative of the amplitude a cell can shorten during contraction; maximal velocities of cell shortening and relengthening ( ± dl/dt) -indicative of peak ventricular contractility; time-to-PS (TPS) -indicative of systolic duration; time-to-90% relengthening ( TR90 )-indicative of diastolic duration ( 90% rather 100%relengthening was used to avoid noisy signal at baseline concentration). The 360 nm excitation scan was repeated at the end of the protocol and qualitative changes in intracellular Ca2+ concentration were inferred from the ratio of fura-2 fluorescence intensity (FFI) at two wavelengths (360/380). Fluorescence decay time was measured as an indicator of the intracellular Ca2+ clearing rate. Glutathione/glutathione disulfide ratio and ROS generation were detected as the markers of oxidative stress. Results Heart rate was increased while EF was reduced in LPS-FVB mice and heart rate was reduced and EF increased in MT-LPS transgenic mice [(528 ±72) beats/min vs (557 ±69) beats/min, (66 ± 14)% vs (42 ± 10)%, P ＜0.05].Cardiomyocytes from the LPS treated FVB mice displayed significantly reduced peak shortening (PS) and maximal velocity of shortening/relengthening ( ± dl/dt ) associated with prolonged time-to-90%relengthening (TR90), these effects were attenuated in cardiomyocytes from the MT-LPS mice [PS (5 ±1.1 )% vs (7.2 ± 0. 8)%, dl/dt (160 ± 15) μm/s vs (212 ± 36) μm/s, - dl/dt (175 ± 32) μm/s vs (208 ±29)μm/s, TR90 (0.24 ±0.03)s vs (0.19 ±0.02) s, P ＜0.05].LPS treated mice showedsignificantly reduced peak intracellular Ca2 + and electrically- stimulated rise in intracellular Ca2 + as well as prolonged intracellular Ca2+ decay rate without affecting the basal intracellular Ca2+ levels, again, these effects were significantly attenuated in MT-LPS transgenic mice. Metallothionein overexpression also ablated oxidative stress [reduced ROS generation and increased glutathione/glutathione disulfide ratio, ROS(0. 35 ±0.08)A/μg protein vs (0.24 ±0.03) A/μg protein] . GSH/GSSG 2.1 ±0.2 vs 2.6 ±0.4, P ＜0. 05. Conclusion MT overexpression improved cardiac function and ablated oxidative stress in LPS treated mice.
