目的观察慢性低氧时大鼠线粒体呼吸链复合体Ⅰ、Ⅱ、Ⅲ、Ⅴ蛋白表达变化并讨论其病理生理学意义。方法成年雄性Wistar大鼠随机分为慢性低氧(4500m,30d)组和对照组,取双侧腓肠肌,分离线粒体,用Clark氧电极法检测线粒体Ⅲ态呼吸(state3,ST3)、Ⅳ态呼吸(state4,ST4)和呼吸控制率(respiratory control ratio,RCR),用Western blot检测线粒体呼吸链复合体Ⅰ、Ⅱ、Ⅲ、Ⅴ蛋白的表达。结果慢性低氧组大鼠腓肠肌线粒体ST3和RCR显著低于对照组(P<0.05)。慢性低氧组大鼠腓肠肌线粒体复合体Ⅰ30×103亚基、复合体Ⅱ70×103亚基、复合体Ⅴα亚基蛋白表达量显著低对照组(P<0.05)。2组线粒体ST4和复合体Ⅲ核心亚基2蛋白表达无显著性差异(P>0.05)。结论低氧可调节大鼠骨骼机线粒体复合体蛋白非协同性表达,导致线粒体氧化磷酸化功能下降。
Objective: To explore the possible mitochondrial DNA (mtDNA) polymorphism in Han Chinese. Methods: The complete mitochondrial genome of 26 unrelated healthy Han Chinese were extracted and sequenced. Results:The mtDNA nucleotide sites (2 706, 7 028, 8 860, 11 719, and 15 326) were found totally different from the Revised Cambridge Reference Sequence (rCRS). These single nucleotide polymorphisms (SNPs) were 2 706 A→G, 7 028 C→T, 8 860 A→G, 11 719 G→A, 15 326 A→G. Conclusion: These findings provide new insights into the characteristics of Han Chinese mitochondrial genetic diversity.
Objective：To investigate the characteristics of fat metabolism in rat skeletal muscle after hypobaric hypoxia acclimation. Methods： Sprague-Dawley rats were divided into 3 groups randomly： control group （H0）, hypoxic 5-day group （HS）, and hypoxic 15-day group （H15）. Animals of H5 and 15 groups were exposed to hypobaric hypoxia chamber simulating 5 000 m high altitude for 5 d or 15 d respectively, 23 h per day. H0 group stayed outside of chamber The level of fatty acid oxidation and uptake, and glucose oxidation were examined, and the level of non-esterified fatty acids （NEFA）, ATP and phosphocreatine （PCr） were also assayed in rat skeletal muscles. Results： The contents of ATP and PCr in H5 group were lower than those in H0 and H15 groups （P〈0.05）, while there was no significant difference between H0 and H15. Compared with H0, the blood NEFA level in all hypoxia groups was increased significantly （P〈0.05）. The muscle NEFA level in H15 group was greatly higher than that in H0 and H5 groups. The rates of fatty acid oxidation and uptake in H15 group were significantly higher than those in H0 and H5 groups （P〈0.05）, and the rate of glucose oxidation in all hypoxia groups was significantly decreased than that in H0 group （P〈0.05）. Conclusion： It is concluded that the enhanced fat oxidation may be one of the mechanisms in the maintenance of energy homeostasis after hypobaric hypoxic acclimation.
Mao SunzhongGao YuqiChen JianLiu FuyiGao WenxiangHuang JianLiao WeigongCai Mingchun
目的探讨缺氧预适应小鼠脑匀浆去蛋白液(deproteinized brain tissue extracts of hypoxia-preconditioned mice,DHP)对NGF诱导分化的PC12细胞缺氧耐受性的影响及其与腺苷的关系。方法复制缺氧预适应小鼠模型,高氯酸法制备DHP。HPLC法检测DHP中腺苷含量及正常小鼠脑匀浆去蛋白液(deproteinized brain tissue extracts of normal mice,DN)中腺苷含量。在已分化PC12细胞中加入DHP,以DN作对照,以1.0、10.0、100.0μmol/L的腺苷为阳性对照,分别于缺氧(2%O2)培养24、48、72h后检测MTT值、LDH透出率以及72h晚期凋亡率;在DHP、10.0μmol/L腺苷阳性对照组中分别加入腺苷A1、A2A受体阻断剂DPCPX、SCH58261(5.0μmol/L),以DN作对照,缺氧24、48、72h后分别检测各组MTT值、LDH透出率。结果DHP中腺苷含量显著高于DN;缺氧24h时,DHP组MTT值显著高于DN组,其LDH透出率显著低于DN组。随缺氧时间延长,DHP保护作用逐渐减弱,至72h时,DHP组MTT值、LDH透出率、晚期凋亡率与DN组均无显著差异;A2A受体阻断剂SCH58261可阻断DHP的保护作用。结论DHP在缺氧初期对分化PC12细胞的保护作用与缺氧预适应中腺苷含量增加有关,保护作用可能通过A2A受体实现。
