介导感觉生理功能的瞬时受体电位通道蛋白(TRP)家族研究进展

瞬时受体电位通道蛋白(TRP)家族由一类特殊的阳离子通道蛋白组成,在神经细胞及其他非兴奋细胞中有重要作用,其中在介导多种感觉生理功能方面的作用尤其显著.TRP结构与功能的深入研究为阐明感觉生理功能的分子机制提供了重要线索.本文综述TRP家族在温度感受、机械刺激感受、光感受和化学信号感受等方面的研究进展.     

Expression of Na+/HCO3− co‐transporter proteins (NBCs) in rat and human skeletal muscle

Aim: Sodium/bicarbonate co‐transport (NBC) has been suggested to have a role in muscle pH regulation. We investigated the presence of NBC proteins in rat and human muscle samples and the fibre type distribution of the identified NBCs. Methods and results: Western blotting of muscle homogenates and sarcolemmal membranes (sarcolemmal giant vesicles) were used to screen for the presence of NBCs. Immunohistochemistry was used for the subcellular localization. The functional test revealed that approximately half of the pH recovery in sarcolemmal vesicles produced from rat muscle is mediated by bicarbonate‐dependent transport. This indicates that the NBCs are preserved in the vesicles. The western blotting experiments demonstrated the existence of at least two NBC proteins in skeletal muscle. One NBC protein (approximately 150 kDa) seems to be related to the kidney/pancreas/heart isoform NBC1, whereas the other protein (approximately 200 kDa) is related to the NBC4 isoform. The two NBC proteins represent the electrogenic isoforms named NBCe1 and NBCe2. Membrane fractionation and immunofluorescence techniques confirmed that the two NBCs are located in the sarcolemmal membrane as well as in some internal membranes, probably the T‐tubules. The two NBCs localized in muscle have distinct fibre type distributions. Conclusions: Skeletal muscle possesses two variants of the sodium/bicarbonate co‐transporter (NBC) isoforms, which have been called NBCe1 and NBCe2.     

精浆蛋白电泳分析的临床意义

目的为了初步了解男性精浆中的蛋白电泳谱以及蛋白谱与男性生育能力的相关关系。方法通过应用SPIFE3000全自动电泳分析仪对20例对照组(生育组)与140例观察组(不育组)的精浆进行蛋白分离(琼脂糖区带电泳法),建立其精浆蛋白质的特征电泳图谱,并进行对比分析。结果精浆蛋白经酸蓝染色后,区带清晰,从阳极到阴极分为A、B、C、D、E 5条带,电泳各区带百分比含量结果经方差分析,发现不育组与生育组A、C、D、E百分比含量变化有统计学意义(P<0.01),且无精子症患者精浆的蛋白谱有特异的"双峰"特点。结论精浆蛋白区带电泳分析可作为不育症的辅助诊断指标,且将是对男性不育诊断手段的有力补充。     

PCBP1:一种在多水平上参与基因表达调控的蛋白因子

多聚胞嘧啶结合蛋白1 (poly C binding protein-1,PCBP1),属于RNA结合蛋白亚家族,因其具有同RNA的多聚胞嘧啶(poly C)区域特异的结合活性而得名.目前该亚家族共有5个成员:hnRNP K(heterogeneous nuclear ribonucleoprotein K)、PCBP1、PCBP2、PCBP3和PCBP4.PCBP1蛋白在多个水平参与基因的表达调控,如转录、mRNA加工、mRNA的转运、mRNA稳定以及翻译水平调控等.本文对PCBP1基因的结构和生物学功能进行了综述.     

糖尿病大鼠骨折后骨形态发生蛋白-2、胰岛素样生长因子-1的变化

目的 观察糖尿病大鼠骨折后骨形态发生蛋白-2(BMP-2)、胰岛素样生长因子-1(IGF-1)的变化,探讨糖尿病对骨折愈合的影响.方法 70只大鼠随机分为对照组和糖尿病组,均造成左侧胫骨骨折.定期摄X线片,取骨痂HE染色,免疫组化检测骨痂BMP-2、IGF-1,ELISA法检测血清BMP-2、IGF-1.结果 2周BMP-2灰度值:实验组为149±8,对照组为107±7(P＜0.01);2周IGF-1灰度值:实验组为137±9,对照组为103±8(P＜0.01).2周血清BMP-2含量:实验组为(3.45±0.12) ng/ml,对照组为(5.60±0.11) ng/ml(P＜0.01);2周IGF-1含量:实验组为(5.89±0.12) ng/ml,对照组为(8.36±0.11) ng/ml(P＜0.01).结论 糖尿病大鼠骨折后血清及骨痂中BMP-2、IGF-1减少是导致糖尿病大鼠骨折愈合差的原因之一;BMP-2与IGF-1可能存在相互作用.     

运动对大鼠腓肠肌一氧化氮含量和铁转运蛋白表达的影响

目的观察游泳运动后大鼠腓肠肌一氧化氮(NO)含量及铁转运相关蛋白表达的变化,探讨运动对骨骼肌铁代谢的调节机制。方法20只雌性SD大鼠随机分为对照组和运动组(每天游泳1.5小时,6次/周),每组10只。实验10周后分别采用试剂盒测定两组大鼠腓肠肌和血清一氧化氮合酶(NOS)活性及NO含量,免疫组织化学方法测定腓肠肌二价金属离子转运体1(DMT1)、膜铁转运蛋白1(FP1)和转铁蛋白受体1(TfR1)的表达,分析其平均光密度变化。结果(1)运动组大鼠血清和腓肠肌NO含量和NOS活性均显著高于对照组(P<0.05);(2)运动组大鼠腓肠肌DMT1(IRE)和TfR1表达较对照组显著增加,FP1表达显著减少(P<0.05),而DMT1(non-IRE)表达无明显变化。结果提示运动可能通过增加NOS活性刺激NO合成增加,进而调节腓肠肌铁转运蛋白的表达,提高腓肠肌摄铁能力,以满足运动中机体对铁的需求。     

全凭静脉麻醉老龄大鼠海马tau蛋白磷酸化水平与认知功能的关系

目的 探讨咪唑安定、芬太尼、丙泊酚联用对老龄大鼠认知功能的影响以及这种影响是否与海马tau蛋白磷酸化水平有关.方法 雄性18月龄SD大鼠40只,随机分成全麻组和对照组,每组20只.每组分别于处理后第1和第7天各断头处死10只,HE染色光镜下观察海马神经元结构,免疫组化染色法检测海马tall蛋白Thr231和Ser404位点磷酸化蛋白的表达水平.其中后处死大鼠于处理后第1周行水迷宫实验.结果 处理后第1天,全麻组大鼠寻找平台的时间明显长于对照组(P＜0.01),但第2～7天与对照组比较差异无统计学意义.处理后第1天,全麻组海马tau蛋白Thr231位点的磷酸化水平高于对照组(P＜0.05).第7天,两组Thr231、Ser404位点的磷酸化水平差异无统计学意义.光镜下各组大鼠海马神经元结构未见明显异常.结论 咪唑安定、芬太尼、丙泊酚联用可引起老龄大鼠麻醉后第1天出现短暂的认知功能减退,海马tau蛋白Thr231位点的过度磷酸化可能与其有关.     

不同骨延长器治疗肢体畸形并大段骨缺损

[目的]利用Ilizarov支架、Orthofix肢体重建系统（Orthofix LRS）及Hybrid固定系统（Hybrid Fixation System）与Orthofix LRS的组合，对不同的肢体畸形并大段骨缺损进行矫形及骨延长治疗，同时观察其疗效。[方法]自2000年8月-2004年3月分别用Ilizarov支架、Orthofix LRS及Hybrid支架与Orthofix LRS的组合进行骨痂牵开／骨段滑移治疗合并肢体畸形的大段骨缺损。畸形处采用线形／楔形截骨。畸形愈合并骨短缩者楔形截骨后进行骨痂牵开骨延长术，骨不连并畸形及短缩者接合点加压与截骨矫形骨段滑移延长同时进行。[结果]矫正股骨短缩畸形7cm1例，胫骨6例，内翻畸形2例，后成角畸形2例，混合畸形2例。平均延长5．3cm（4．5—7cm），平均延长时间3．5个月，平均延长后外固定时间7个月，无神经血管损伤，膝踝关节活动未受影响。[结论]Ilizarov支架、Orthofix LRS、Hybrid固定系统与Orthofix LRS的组合用于骨痂牵开／骨段滑移治疗合并肢体畸形的大段骨缺损均能达到矫形及骨延长的治疗目的。Orthofix LRS及Hybrid固定系统与Orthofix LRS的组合较Ilizarov支架操作简便，安全可靠，患者乐于接受。     

异体脱钙骨基质复合bBMP修复兔桡骨骨缺损

目的：探讨异体脱钙骨基质复合BMP修复节段性骨缺损的能力。方法：64只新西兰大白兔采用桡骨15mm节段性骨缺损模型，随机分为4组，A组植入异体脱钙骨基质(Demineralized Bone Matrix,DBM)与牛骨形态发生蛋白(Bovine Bone Morphogentic Protein,bBMP)复合材料，B组植入异体DBIM，C组植入异体骨粒，D组为空白对照组。术后4、8、12、16w，进行放射学检查、病理组织学检查和计算机图像分析新生骨面积。结果：异体DBM与bBMP复合材料组骨生成、新骨面积和骨连接情况明显优于异体DBM组、异体骨粒组和空白对照组。结论：异体DBM复合BMP材料通过骨诱导和骨传导两种方式修复骨缺损，是一种较为理想、具有高效成骨活性的植骨材料。     

Brain uptake of radiolabeled N‐oleoyl‐dopamine in the rat

N‐acyl‐dopamines are a novel class of biologically active lipids that have recently been identified in the brain and have the potential to interact with neural signaling pathways. This study seeks to determine the ability of N‐oleoyl‐dopamine, a synthetic amide of oleic acid and dopamine, to cross the blood brain barrier. We determined the tissue content of radioactivity in selected brain regions, in a short‐run study design, following injections of [³H]N‐oleoyl‐dopamine (0.4 µCi) into the internal carotid artery in the rat. These results were compared with intracarotid injections of [³H]dopamine and with intravenous injections of both radiolabeled compounds. The level of radioactivity was determined using liquid scintillation and was expressed as the percentage of its total dose injected per gram of tissue. We found that the 15‐min brain uptake of radioactivity, with no distinct regional variations, amounted to about 6% following the intracarotid [³H]N‐oleoyl‐dopamine, which was a significant 3–4‐fold increase over that following similar administration of [³H]dopamine. Intravenous injections of [³H]N‐oleoyl‐dopamine gave a much smaller yield of radioactivity in brain tissue samples which was still severalfold greater than that for intravenous [³H]dopamine. Qualitative thin‐layered chromatography screening showed the presence of unchanged N‐oleoyl‐dopamine in the brain following injections. We conclude that N‐oleoyl‐dopamine has an appreciable ability to cross the blood‐brain barrier, which contrasts the limited transfer of dopamine alone. N‐oleoyl‐dopamine might exert physiological effects due to its known affinity for the central vanilloid receptors or to better satisfying the brain tissue demand for dopamine. The study suggests a potential pharmacological role for N‐oleoyl‐dopamine delivered exogenously in helping regulate the brain function. Drug Dev. Res. 60:217–224, 2003. © 2003 Wiley‐Liss, Inc.