间歇低氧促进大鼠海马神经细胞低氧诱导因子1和存活素的表达

目的通过模拟阻塞性睡眠呼吸暂停低通气综合征的发病特征,建立大鼠间歇性低氧(IH)模型,观察慢性IH早期大鼠海马CA1区低氧诱导因子1(HIF-1)、存活素(survivin)的表达及细胞凋亡情况。方法72只雄性Wistar大鼠随机均分为对照组和间歇低氧(50mL/LIH)组,对照组向低氧箱内持续注入压缩空气,间歇低氧组分别暴露于间歇性低氧条件下(暴露时间每天7h,持续时间分别为3、7、14、21d)。免疫组织化学染色检测海马CA1区HIF-1、survivin蛋白的表达,原位末端标记法检测神经细胞凋亡。结果与对照组比较,海马CA1区神经细胞凋亡指数在间歇低氧3d时无明显差异,间歇低氧7、14、21d组凋亡指数均明显高于对照组,于21d达高峰。与对照组比较,间歇低氧组HIF-1、survivin蛋白的表达在各时间点均增加,14d达峰值后逐渐下降,两者表达呈正相关关系(r=0.836)。结论早期间歇低氧可诱导海马CA1区HIF-1、survivin蛋白的表达,二者在神经细胞凋亡的调控中可能有一定作用。     

短期间歇和急性低氧对大鼠快慢肌萎缩的影响及其作用机制

目的:探讨不同低氧干预模式对大鼠快肌和慢肌萎缩的影响差异及可能的分子机制.方法:24只10周龄雄性SD大鼠分为常氧对照组(C组)、短期间歇低氧组(IH组,于12.4％O2暴露8 h/d,持续4周)和急性低氧组(AH组,连续3 d暴露于12.4％O2),每组8只.干预后测定抓力,胫骨前肌(TA,快肌)和比目鱼肌(SOL,...     

慢性间歇性低氧对麻醉大鼠心血管系统的影响

目的观察慢性间歇低氧对麻醉大鼠心血管系统的影响。方法通过随机数字表法将72只SD雄性大鼠分为3组,每组24只,分别为常氧对照组(对照组)、常氧麻醉组(模型组)和慢性间歇低氧组(低氧组)。对照组呼吸正常空气,模型组给予用10%水合氯醛0.3 m L/kg腹腔注射麻醉,低氧组在模型组的基础上给予8 h/d慢性间歇低氧刺激。比较各组大鼠的超声心动数据、血压、内皮素-1、内皮型一氧化氮合酶(e NOS)的差异。28 d后处死大鼠,观察各组大鼠心肌细胞结构的改变。结果对照组大鼠心肌形态正常,细胞排列均匀,未见肿胀和炎症;模型组大鼠心肌细胞排列较均匀,未出现肥大和炎性改变;低氧组大鼠心肌细胞排列不均匀,肥大、肿胀、变形,核大深染,心肌组织有明显炎性改变。对照组大鼠心肌细胞核及胞浆呈均匀排列,形态较均一,与对照组比较,模型组细胞形态变化不大,低氧组大鼠心肌细胞形态明显改变,细胞形态、大小的不均一增加,凋亡细胞的颜色由浅变深。低氧组大鼠尾动脉收缩压明显高于对照组和模型组,LVEF显著低于对照组和模型组,差异均具有统计学意义(P0.05)。超声检测值提示低氧组大鼠LVID稍微变大,左心腔扩大,舒张功能尚正常,低氧组和模型组的LVDs均明显高于对照组,差异具有统计学意义(P0.05),低氧组大鼠的RBC、HCT显著高于对照组和模型组,差异具有统计学意义(P0.05),而低氧组大鼠的dp/dtmax和-dp/dtmax显著高于对照组和干预组,差异具有统计学意义(P0.05),低氧组的血清内皮素-1水平显著高于对照组和模型组,而低氧组的血清NO_2~-/NO_3~-总和与eNOS显著低于对照组和模型组,差异均具有统计学意义(P0.05)。结论慢性间歇低氧可造成麻醉大鼠心功能损伤,此种损伤可能通过氧化应激引起血清内皮素-1、NO含量失衡,导致内皮功能障碍,进而损伤心肌。     

Construction of An Experimental Hypogiossal Nerve Signals Record Platform in Rat Model of Chronic Intermittent Hypoxia in Vivo

目的:建立一种以模拟阻塞性睡眠呼吸暂停低通气综合征的慢性间歇低氧大鼠模型为基础、探讨在体舌下神经电信号活动的实验平台.方法:慢性间歇低氧大鼠模型由气源(氮气及空气)、电磁阀控制系统、间歇低氧动物仓、以及实验动物(大鼠)组成,按照实验要求对大鼠交替给予氮气和空气,每天8h,连续处理7周后,分离舌下神经,应用多通道生物信号采集与处理系统对舌下神经电信号进行处理与分析.结果:预实验结果显示,慢性间歇低氧大鼠模型能够模拟人体阻塞性睡眠呼吸暂停低通气综合征的病理生理特征,所记录的电信号稳定、可靠.结论:慢性间歇低氧大鼠模型简单、易行、实用、重复性好,记录的舌下神经电信号稳定、可靠,达到实验设计要求.     

肾上腺髓质素缓解大鼠低氧性肺动脉高压

目的探讨肾上腺髓质素(ADM)对大鼠低氧性肺动脉高压的防治作用及机制。方法雄性Wistar大鼠18只,分为对照组、低氧组和低氧 ADM组,每组6只。持续皮下注射ADM1-50后,测定平均肺动脉压(mPAP)、右心室肥大指数RV/(LV S)、肺小动脉病理及形态计量学和体循环平均压(mSBP),放免法测定肺动脉血浆ADM水平,原位杂交测定肺动脉ADMR mRNA的表达。结果①低氧组大鼠mPAP,RV/(LV S),管壁厚度与血管外径比值(MT%)及管壁面积与血管面积比值(MA%)均显著升高(P<0.01);ADM组显著缓解以上变化(P<0.01)。②低氧组与低氧 ADM组肺动脉血浆ADM浓度均高于对照组,且低氧 ADM组较低氧组ADM浓度低(P<0.05)。③低氧组与低氧 ADM组的ADMR mRNA表达较对照组增强(P<0.01)。结论持续皮下注射ADM对慢性低氧所致的肺动脉高压及肺血管重塑有预防和部分逆转作用。     

依达拉奉对慢性间歇低氧大鼠前额叶生长相关蛋白43、Nogo-A表达的影响

目的:观察依达拉奉对慢性间歇低氧大鼠前额叶皮质生长相关蛋白43(GAP-43)、Nogo-A表达的影响。方法:将成年雄性Wistar大鼠,随机分为对照组、5%间歇低氧组、依达拉奉组。5%间歇低氧组与依达拉奉组分别暴露于间歇性低氧条件下。每日7:00给予依达拉奉注射液3 mg/kg尾静脉注射,通过化学比色法检测超氧化物歧化酶(SOD)及丙二醛(MDA),应用免疫组织化学及免疫印迹检测大鼠前额叶皮质GAP-43、Nogo-A的蛋白表达。结果:与对照组比较,5%间歇低氧组及依达拉奉组MDA含量于各个时间点均逐渐增加,SOD逐渐下降,GAP-43、Nogo-A蛋白的表达于各个时间点增加,并于14d达最高值;与5%间歇低氧组比较,依达拉奉组MDA及Nogo-A的表达降低,SOD及GAP-43的表达增加。结论:依达拉奉可能通过抑制氧化应激,促进大鼠前额叶皮质内GAP-43表达及抑制Nogo-A表达,促进神经细胞轴突再生。     

大鼠慢性间歇性低氧后氧自由基/JNK信号通路介导神经损伤的机制

目的　探讨氧自由基/JNK信号通路在慢性间歇性低氧大鼠神经损伤中的作用。 方法 　160只雄性SD大鼠随机分成对照组（n=40）、轻度间歇低氧组（n=40）、中度间歇低氧组（n=40）、重度间歇低氧组（n=40）。对照组暴露于空气中,间歇低氧组分别暴露于不同低氧条件下（100 ml/L、75 ml/L和50 ml/L,暴露时间每天8 h,持续时间2、4、6、8周）,电镜观察海马区神经细胞超微结构,采用硫代巴比妥酸法检测大脑组织丙二醛(MDA)水平;免疫印迹和免疫组化法检海马区磷酸化JNK和c-fos蛋白表达水平,原位缺口末端标记法（TUNEL）检测凋亡细胞。 结果　与对照组比较,随低氧时间的延长,三组间歇性低氧组大鼠海马神经元结构损伤;MDA水平、磷酸化JNK及c-fos表达增多,TUNEL阳性细胞增多（P＜　0.05）;上述变化在重度间歇性低氧组最为显著（P＜0.05）;轻中度间歇性低氧组中MDA水平、磷酸化　JNK及c-fos和TUNEL阳性细胞6周达高峰,两组比较二者差异无统计学意义;重度间歇性低氧组MDA水平、磷酸化JNK及c-fos和TUNEL阳性细胞8周达高峰,与轻中度间歇性低氧组比较,差异显著。 结论　慢性间歇性低氧后氧自由基激活的JNK信号通路,通过调控c-fos表达介导神经细胞凋亡。     

美托洛尔对充血性心力衰竭大鼠血浆醛固酮浓度、心肌纤维化和心室重构的影响

目的:探讨美托洛尔对充血性心力衰竭(CHF)大鼠血浆醛固酮(ALD)浓度的影响及防治心肌纤维化及心室重构的作用。方法:雄性SD大鼠30只,随机选择20只皮下注射异丙基肾上腺素二次(170mg/kg/次),6周后左室射血分数≤45%确定造模成功;将模型大鼠随机分为模型组(n=10)和美托洛尔治疗组(n=10,8mg/kg/天,共治疗12周);另10只大鼠作为正常对照组。18周后进行心功能指标、血浆ALD浓度检测,并取心肌观察组织形态学及胶原纤维染色。结果:(1)与对照组相比,模型组心功能指标明显恶化,血浆ALD显著升高(P0.01),心肌纤维化和心室重构明显;(2)与模型组比较,美托洛尔组心功能明显好转,血浆ALD明显下降(P0.01),心肌纤维化和心室重构明显改善。结论:美托洛尔能通过降低CHF大鼠血浆ALD浓度而改善心功能,逆转心室重塑。     

血管内皮生长因子和低氧诱导因子-1α与慢性马兜铃酸肾病大鼠肾间质纤维化的关系

目的 探讨血管内皮生长因子(VEGF)及低氧诱导因子-1α(HIF-1α)等与慢性马兜铃酸肾病(CAAN)大鼠肾间质纤维化的关系.方法 36只Wistar大鼠分2组:关木通组(24只)予关木通水煎剂连续灌胃12周,对照组(12只)予等量自来水连续灌胃12周;在4、8、12、16周末分别处死关木通组6只、对照组3只,留取肾组织.常规HE、Masson 染色,免疫组化检测低氧诱导因子-1α(HIF-1α)、血管内皮生长因子(VEGF)和纤维连接蛋白(FN)表达并进行半定量分析.结果 与对照组相比,关木通组肾小管间质病变逐渐加重,16周末呈典型的寡细胞性肾间质纤维化; VEGF表达短暂上升随后下降;HIF-1α、FN表达逐渐增多,与肾间质面积正相关.结论 在CAAN 中,HIF-1α表达多少引起VEGF的变化与CAAN大鼠肾间质纤维化关系密切;FN在CAAN大鼠肾间质纤维化发展过程中起到重要的作用.     

TGF-β1诱导成肌纤维细胞形成在低氧性

目的探讨转化生长因子-β1(TGF-β1)诱导成肌纤维细胞形成在低氧性肺血管重塑中的作用。方法40只成年雄性Wistar大鼠随机分成:对照组、低氧3、7、14和21 d组,每组8只,测大鼠平均肺动脉压(mPAP)、血管形态学指标、右室肥大指数(RVHI);免疫组化检测α-平滑肌肌动蛋白(α-SMA)的表达,原位杂交和免疫组化检测TGF-β1基因表达,透射电镜观察腺泡内血管壁细胞表型,细胞培养观察低氧和TGF-β1诱导人胚肺成纤维细胞是否发生表型转化。结果(1)低氧7 d后大鼠mPAP升高(P<0.05)。低氧14 d后出现肺血管重塑、右心室肥大。(2)从低氧7 d开始无肌型动脉、部分肌型动脉、肌型动脉的构成比分别是39%、46%和15%,与对照组60%、35%和5%比较差异显著(P<0.005)。(3)腺泡内肺动脉管壁α-SMA的表达随着低氧时间的延长逐渐增多。低氧14 dTGF-β1mRNA表达增高(P<0.01);TGF-β1蛋白在对照组呈弱阳性,低氧3 d表达增强(P<0.01),低氧7 d达高峰(P<0.01)。(4)透射电镜证实成肌纤维细胞含有特异性的微丝和丰富的粗面内质网。(5)细胞培养表明低氧能够刺激成纤维细胞发生表型转化,TGF-β1能够促进成纤维细胞表型转化的发生。结论转化生长因子β1诱导成肌纤维细胞形成是低氧性肺血管重塑的重要原因之一。     

Rho激酶抑制剂对压力超负荷大鼠心肌纤维化的影响

目的:观察Rho激酶抑制剂法舒地尔对大鼠心肌纤维化的影响。方法:采用腹主动脉缩窄术制备SD大鼠心肌纤维化模型,动脉夹闭4周后,随机分为4组:假手术组(Sham组)、模型组(Model组)、法舒地尔高剂量(FH,30mg/Kg/天)组和法舒地尔低剂量(FL,10mg/Kg/天)组。术后8周末,计算各组大鼠心脏质量指数(HWI)、左室质量指数(LVWI),观察心肌组织HE染色和Masson染色,碱水解法测定心肌组织羟脯氨酸(HYP)含量,免疫组化分析磷酸化的肌球蛋白磷酸酶靶蛋白亚基1(p-MYPT1)、转化生长因子β1(TGF-β1)和结缔组织生长因子(CTGF)水平。结果:与Sham组相比,Model组大鼠LVWI及HYP含量显著升高(P<0.01),心肌细胞排列紊乱,间质大量胶原纤维沉积,心肌组织p-MYPT1水平升高(P<0.01),TGF-β1、CTGF表达升高(P<0.01);与Model组相比,FH组和FL组大鼠LVWI及HYP含量降低(P<0.05),间质胶原蛋白沉积程度减轻,心肌组织p-MYPT1、TGF-β1、CTGF水平均降低(P<0.05或P<0.01)。结论:Rho激酶参与压力超负荷诱导的大鼠心肌纤维化,法舒地尔抑制心肌纤维化进展的作用与TGF-β1和CTGF水平的降低有关。     

低氧训练与低氧大鼠心肌细胞凋亡及凋亡因子的表达

背景：低氧训练时,机体既要承受运动负荷,同时处于外界的低氧环境,此时, 心组织将如何适应其变化?其机制研究国内外较少。 目的：观察低氧与低氧训练对大鼠心肌细胞凋亡及Bax及Bcl-2表达的影响。 方法：SD大鼠共60只随机分为6组,常氧组、低氧8 h组、低氧12 h组、常氧训练组、低氧8 h训练组和低氧12 h训练组,每组10只。后3组大鼠每天在坡度为0的动物跑台上以25 m/min的速度训练1 h。训练完后,将低氧8 h组、低氧8 h训练组和低氧12 h组、低氧12 h训练组放入氧体积分数为12.5%(相当于海拔4 000 m)的低氧舱内8 h和12 h。实验期为4周,5 d/周。最后1次实验结束后24 h,大鼠均实施速眠新Ⅱ腹腔麻醉后取材,采用苏木精-伊红染色、原位末端脱氧核糖核苷酸转移酶介导的dUTP缺口末端标记法及蛋白免疫组织化学法检测各组大鼠心肌细胞凋亡和Bcl-2、Bax蛋白表达。 结果与结论：①与常氧组相比, 低氧12h组、常氧训练组、低氧训练组心肌细胞凋亡指数均显著增加 (P < 0.05) ;低氧12 h训练组心肌细胞凋亡指数显著多于常氧训练组和低氧8h训练组(P < 0.05) 。②与常氧组比较,其他各组Bcl-2、Bax、Bcl-2/Bax均显著性增高(P < 0.05) ;常氧训练组Bcl-2、Bax、Bcl-2/Bax表达显著高于低氧 8 h组,显著低于低氧12 h训练组(P < 0.05) ;低氧12 h训练组Bcl-2、Bax、Bcl-2/Bax表达比低氧12 h组、低氧8 h训练组显著增加(P < 0.05)。提示低氧、低氧训练可诱导大鼠心肌细胞Bcl-2、Bax蛋白表达, 运动时低氧刺激与细胞凋亡率、凋亡指数及病理损伤有关,其中以低氧12 h后运动训练组最明显,心肌细胞的凋亡调控与Bcl-2和Bax相关。     

Apolipoprotein E-deficient mice exhibit increased vulnerability to intermittent hypoxia-induced spatial learning deficits

Exposure to intermittent hypoxia, such as occurs in sleep-disordered breathing, is associated with oxidative stress, cognitive impairments, and increased neuronal apoptosis in brain regions involved in learning and memory. Apolipoprotein E (ApoE) has been implicated in neurodegenerative disorders, and in vitro studies suggest that one of the functions of ApoE may be to confer protection from oxidant stress-induced neuronal cell loss. Therefore, we hypothesized that ApoE-deficient (ApoE-/-) mice would display increased cognitive impairments following intermittent hypoxia. Twenty-four young adult male mice (ApoE-/-) and 24 wild-type littermates (ApoE +/+) were exposed to 14 days of normoxia (room air; n=12 per group) or intermittent hypoxia (5.7% O2 alternating with 21% O2 every 90 seconds, 12 daylight hours per day; n=12 per group). Behavioral testing consisting of a standard place-training reference memory task in the water maze revealed that ApoE+/+ and ApoE-/- mice exposed to intermittent hypoxia were found to require significantly longer times (latency) and distances (pathlength) to locate the hidden platform (P < .005), compared to mice exposed to room air. However, only intermittent hypoxia-exposed ApoE-/- mice were impaired on the final two days of training (P < .03), as well as on measures of spatial bias conducted 24 hours after completion of training (P < .02). Furthermore, increased prostaglandin E2 and malondiadehyde concentrations were present in hippocampal brain tissues following intermittent hypoxia but were significantly higher in ApoE-/- mice (P < .01). Thus, decreased ApoE function is associated with increased susceptibility to neurocognitive dysfunction in a rodent model of sleep-disordered breathing and may underlie the increased prevalence of Apolipoprotein E4 in patients with sleep-disordered breathing.     

Effect of fasudil on hypoxic pulmonary hypertension and right ventricular hypertrophy in rats

Objective: To investigate whether right ventricular hypertrophy in hypoxic pulmonary hypertension (HPH) rats could be prevented by treatment with Rho kinase inhibitor fasudil. Methods: The rat model of pulmonary hypertension was established by exposing rats to normobaric intermitent hypoxia [(10±0.5)% O₂]. Twenty-four Spraque-Dawley male rats were randomly divided into control group, hypoxic model group and hypoxia with fasudil groups (n=8 each). The mean pulmonary arterial pressure (mPAP), and right ventricle hypertrophy index (RVHI) were measured. Ultrastructure of the right ventricular myocardial cells was observed under transmission electron microscope (TEM). –Results: The level of mPAP (31.38±1.98) mmHg and RVHI (0.47±0.03) were significantly higher in the hypoxic model group than (15.25±0.91) mmHg and (0.25±0.02) in control group respectively (P<0.01). Transmission electron microscope (TEM) revealed the model group right ventricular mitochondria increased significantly, swelling, cristae blurred, lost, heart muscle Siming dark band was not clear. The level of mPAP (16.63±1.53) mmHg and RVHI (0.27±0.02) were significantly lower in fasudil treatment group than in model group respectively (P<0.01). After the intervention of fasudil right ventricular myocardial injury was significantly reduced. Conclusions: Fasudil may partly prevent and reverse the development of pulmonary hypertension and right ventricular hypertrophy and myocardial cell injury.     

Fasudil,an inhibitor of Rho-associated coiled-coil kinase,attenuates hyperoxia-induced pulmonary fibrosis in neonatal rats

Background: Oxygen therapy is important during the management of high-risk neonatal infants, such as those with preterm birth, low birth weight, and asphyxia. However, prolonged exposure to high oxygen concentrations can readily lead to diffuse nonspecific inflammation, which promotes airway remodeling and pulmonary fibrosis. The Rho/Rho-associated coiled-coil kinase (Rho/ROCK) signaling pathway plays an important role in numerous developmental and proliferative diseases. This study was performed to determine the efficacy of ROCK inhibitor fasudil in blocking the development of hyperoxia-induced lung injury and fibrosis in neonatal rats. Methods: Neonatal rats were randomly divided into four groups: air + saline group, air + fasudil group, hyperoxia + saline group, and hyperoxia + fasudil group. The hyperoxia + saline and Hyp + fasudil groups were exposed to 95% oxygen for 21 days and administered intraperitoneal saline or fasudil once daily. The air + saline and air + fasudil group were exposed to 21% oxygen (room air) and administered the same volume of intraperitoneal saline or fasudil. Results: Fasudil-treated rats exhibited improved histopathological changes and decreased lung hydroxyproline content. Fasudil attenuated the protein level of alpha-smooth muscle actin, transforming growth factor-β1, and connective tissue growth factor. Additionally, fasudil reduced the activation of ROCK1 and myosin phosphatase targeting subunit 1 protein in the Rho/ROCK signaling pathway. Conclusions: Fasudil may be a potentially effective therapeutic drug for hyperoxia-induced pulmonary fibrosis.     

西拉普利对低氧大鼠肺动脉和心肌细胞增殖的抑制作用

目的：探索cilazapril 对低氧大鼠肺血管和心肌细胞增殖的抑制机理。 方法： 采用生化、放射免疫、免疫组织化学、细胞凋亡标记和血流动力学技术研究低氧肺血管及心肌细胞增殖和结构重建。 结果： （1）低氧大鼠mPAP显著增高，伴有肺动脉血管管腔狭窄、管壁增厚，心肌肥大，R/L+S增高。（2）B组、C组大鼠肺动脉和右心肌细胞增殖指数（PI）均分别明显高于A组，而C组明显低于B组。ET-1免疫组化染色阳性细胞主要分布在肺动脉血管壁和心肌细胞上，染色程度由强到弱依次为B组>C组>A组。（3）B组大鼠ET-1水平和ACE活性明显高于A组，而C组显著低于B组。（4）直线相关分析显示ET-1、ACE分别与R/(L+S)、mPAP、肺动脉PI、心肌PI呈正相关；多元回归分析显示ET-1和ACE可能是影响PI的主要因素。 结论： 低氧大鼠存在细胞过度增殖状态，继发肺血管、右心结构重建是低氧性肺动脉高压发病机理之一。Cilazapril通过抑制ACE和ET-1的促增殖作用，阻止肺血管及心肌重建，对低氧性肺动脉高压的防治有一定作用。     

RhoA经基质金属蛋白酶-3、-9通路介导心力衰竭大鼠心肌重塑及心功能恶化

目的:探讨RhoA、Rho激酶、基质金属蛋白酶家族(MMPs)MMP-3、MMP-9表达与心肌重塑及心功能损害的关系。方法:建立假手术组及心力衰竭大鼠(造模12周及20周)模型。应用Nikon 4多导生理记录仪检测血液动力学指标以评价心功能情况,心肌肥厚指数及H-E染色评价心肌重塑情况,并采用RT-PCR方法检测各组大鼠心肌组织RhoA、Rho激酶及MMP-3、MMP-9基因表达。结果:造模20周、造模12周心力衰竭组大鼠与假手术组大鼠对比,随心肌重塑加重、心功能恶化,RhoA、Rho激酶及MMP-3、MMP-9基因表达显著增加,且直线相关分析结果显示RhoA基因表达与Rho激酶、MMP-3、MMP-9基因表达呈正相关趋势。结论:RhoA可能通过刺激MMP-3、MMP-9的表达引起细胞外基质结构发生改变,引起心肌重塑和心功能恶化。     

The role of NADPH oxidase in chronic intermittent hypoxia-induced pulmonary hypertension in mice

Obstructive sleep apnea, characterized by intermittent periods of hypoxemia, is an independent risk factor for the development of pulmonary hypertension. However, the exact mechanisms of this disorder remain to be defined. Enhanced NADPH oxidase expression and superoxide (O2(-).) generation in the pulmonary vasculature play a critical role in hypoxia-induced pulmonary hypertension. Therefore, the current study explores the hypothesis that chronic intermittent hypoxia (CIH) causes pulmonary hypertension, in part, by increasing NADPH oxidase-derived reactive oxygen species (ROS) that contribute to pulmonary vascular remodeling and hypertension. To test this hypothesis, male C57Bl/6 mice and gp91phox knockout mice were exposed to CIH for 8 hours per day, 5 days per week for 8 weeks. CIH mice were placed in a chamber where the oxygen concentration was cycled between 21% and 10% O2 45 times per hour. Exposure to CIH for 8 weeks increased right ventricular systolic pressure (RVSP), right ventricle (RV):left ventricle (LV) + septum (S) weight ratio, an index of RV hypertrophy, and thickness of the right ventricular anterior wall as measured by echocardiography. CIH exposure also caused pulmonary vascular remodeling as demonstrated by increased muscularization of the distal pulmonary vasculature. CIH-induced pulmonary hypertension was associated with increased lung levels of the NADPH oxidase subunits, Nox4 and p22phox, as well as increased activity of platelet-derived growth factor receptor beta and its associated downstream effector, Akt kinase. These CIH-induced derangements were attenuated in similarly treated gp91phox knockout mice. These findings demonstrate that NADPH oxidase-derived ROS contribute to the development of pulmonary vascular remodeling and hypertension caused by CIH.     

缺氧、复氧条件下低氧反应元件（HRE）对心肌细胞转染hVEGF165基因表达的调控作用

目的：探讨缺氧、复氧条件下，低氧反应元件(HRE)作为氧条件基因表达控制开关，对心肌细胞转染rAAV-HRE9-hVEGF165基因表达的调控作用。方法:分离新生SD大鼠心肌细胞,采用无血清培养,将在HEK293T细胞进行包装后获得的腺相关病毒转染培养的心肌细胞。实验共分为8组：Ⅰ组（空白对照组）：常氧培养 24 h（氧浓度21％）；Ⅱ组（缺氧对照组）：常氧培养16 h，缺氧8 h（氧浓度1％）；Ⅲ组（转基因对照组）：常氧培养 24 h；Ⅳ组（转基因缺氧1组）：转基因后缺氧8 h；Ⅴ组（复氧1组）：常氧培养16 h，缺氧8 h、复氧4 h；Ⅵ组（复氧2组）：常氧培养16 h，缺氧8 h、复氧8 h；Ⅶ组（复氧3组）：常氧培养16 h，缺氧8 h、复氧12 h；Ⅷ组（转基因缺氧2组）：转基因后常氧培养16 h，缺氧20 h。ELISA法测定培养液VEGF蛋白含量；细胞免疫荧光染色及RT-PCR分别检测细胞内VEGF蛋白及VEGF165 mRNA的表达。结果:95%的培养心肌细胞可见自律搏动，cTn-I染色阳性率为86%；病毒转染率约为87%。Ⅳ、Ⅴ、Ⅷ组培养液中VEGF蛋白含量显著高于其它各组（P<0.01），细胞免疫荧光VEGF蛋白染色呈阳性；RT-PCR测定显示，Ⅳ、Ⅴ及Ⅷ组可见484 bp目的条带。结论：rAAV-HRE9-hVEGF165可成功地转染原代培养心肌细胞，在缺氧环境下，受HRE的调控，VEGF165 mRNA及VEGF165蛋白可有效表达，而在常氧状态下，目的基因的表达及蛋白合成即行中止。