Regulation of muscle creatine kinase by phosphorylation in normal and diabetic hearts

Protein kinase C (PKC) is an important signaling molecule in the heart, but its targets remain unclear. Using a PKC substrate antibody, we detected a 40-kDa phosphorylated cardiac protein that was subsequently identified by tandem mass spectroscopy as muscle creatine kinase (M-CK) with phosphorylation at serine 128. The forward reaction using ATP to generate phosphocreatine was reduced, while the reverse reaction using phosphocreatine to generate ATP was increased following dephosphorylation of immunoprecipitated M-CK with protein phosphatase 2A (PP2A) or PP2C. Despite higher PKC levels in diabetic hearts, decreased phosphorylation of M-CK was more prominent than the reduction in its expression. Changes in CK activity in diabetic hearts were similar to those found following dephosphorylation of M-CK from control hearts. The decrease in phosphorylation may act as a compensatory mechanism to maintain CK activity at an appropriate level for cytosolic ATP regeneration in the diabetic heart. Received 15 September 2008; received after revision 30 September 2008; accepted 13 October 2008     

下肢运动方式对COPD有创机械通气患者肌力的影响

为了比较运动方式对COPD有创机械通气患者肌力的影响,对入住ICU的112例COPD有创机械通气患者进行分组对照实验.按预设的早期运动方案,两组患者下肢运动方式不一样,干预组采用床上脚踏车进行下肢运动,对照组采用手动下肢运动.结果表明,脱离ICU监护时下肢主、客观肌力指标、ICU活动水平和Barthel指数评分以及出院时Barthel指数评分,两组患者之间差异有统计学意义(P<0.05), 脱离ICU监护时上肢主、客观肌力指标和出院6个月Barthel指数,两组患者之间差异无统计学意义(P>0.05),说明COPD有创机械通气患者实施床上脚踏车运动安全可行,且可以改善下肢肌力和运动水平,促进日常生活功能的恢复.     

下肢运动方式对COPD有创机械通气患者肌力的影响

为了比较运动方式对COPD有创机械通气患者肌力的影响,对入住ICU的112例COPD有创机械通气患者进行分组对照实验.按预设的早期运动方案,两组患者下肢运动方式不一样,干预组采用床上脚踏车进行下肢运动,对照组采用手动下肢运动.结果表明,脱离ICU监护时下肢主、客观肌力指标、ICU活动水平和Barthel指数评分以及出院时Barthel指数评分,两组患者之间差异有统计学意义(P<0.05), 脱离ICU监护时上肢主、客观肌力指标和出院6个月Barthel指数,两组患者之间差异无统计学意义(P>0.05),说明COPD有创机械通气患者实施床上脚踏车运动安全可行,且可以改善下肢肌力和运动水平,促进日常生活功能的恢复.     

虎纹蛙蝌蚪与幼蛙肌肉蛋白质的双向电泳图谱对比分析

双向电泳技术是蛋白质组研究的核心技术之一。通过对虎纹蛙蝌蚪与幼蛙的肌肉进行双向电泳并对其图谱对比分析,为其今后进行蛋白质组学的研究打下基础。     

Time course of the regeneration of the endplate zone after autologous muscle transplantation

Summary Reinnervation of transplanted muscles occurs in 2 steps. During the first 5 months the motor axon terminals innervate primarily the border of the original endplate zone, re-establishing its previous outline. In the next 4 months, by further ramifying of the axons, new nerve-muscle contacts are formed exclusively within the boundaries of this zone.     

Differential expression analysis and regulatory network reconstruction for genes associated with muscle growth and adipose deposition in obese and lean pigs

During the growth and development of skeletal muscle cells and adipose cells, the regulatory mechanism of micro-effect polygenes determines porcine meat quality, carcass characteristics and other relative quantitative traits. Obese and lean type pig breeds show obvious differences in muscle growth and adipose deposition; however, the molecular mechanism underlying this phenotypic variation remains unknown. We used pathway-focused oligo microarray studies to examine the expression changes of 140 genes associated with muscle growth and adipose deposition in longissimus dorsi muscle at six growth stages （birth, 1, 2, 3, 4 and 5 months） of Landrace （a leaner, Western breed） and Taihu pigs （a fatty, indigenous, Chinese breed）. Variance analysis （ANOVA） revealed that differences in the expression of 18 genes in Landrace pigs and three genes in Taihu pigs were very significant （FDR-adjusted permutation, P 〈 0.01） and differences for 22 genes in Landrace pigs and seven genes in Taihu pigs were significant （FDR-adjusted permutation, P 〈 0.05） among six growth stages. Clustering analysis revealed a high level of significance （FDR-adjusted, P 〈 0.01） for four gene expression patterns, in which genes that strongly up-regulated were mainly associated with the positive regulation of myofiber formation and fatty acid biogenesis and genes that strongly down-regulated were mainly associated with the inhibition of cell proliferation and positive regulation of fatty acid β-oxidation. Based on a dynamic Bayesian network （DBN） model, gene regulatory networks （GRNs） were reconstructed from time-series data for each pig breed. These two GRNs initially revealed the distinct differences in physiological and biochemical aspects of muscle growth and adipose deposition between the two pig breeds; from these results, some potential key genes could be identified. Quantitative real-time RT-PCR （QRT-PCR） was used to verify the microarray data for five modulated genes, and a good correlation between     

The generation of new ‘white’ muscle fibers by budding in the lateral musculature of elversAnguilla anguilla (L.) during normal development

Summary The elver is a developmental stage of the European eel Anguilla anguilla (L.). During its growth, relatively large numbers of new muscle fibers are formed in the lateral musculature. We investigated the origin of these fibers. They proved to originate from already existing fibers by budding.     

蔗糖与西洋参对小鼠糖原影响的试验研究

目的初步研究蔗糖和西洋参及二者配伍对小鼠糖原的影响。方法用三批动物,每批40只昆明种小鼠,按体重分成4组,分别给予去离子水、0.7g/kg蔗糖水、0.33g/kg西洋参及西洋参蔗糖配伍。30d后分别测定小鼠运动前、运动后即刻及运动后休息36h的血糖、肝糖原和肌糖原含量。结果(1)与阴性组比较,西洋参和蔗糖可增加运动前的肝糖原储备(P<0.01,P<0.05),而蔗糖与配伍组可增加运动后即刻的肝糖原含量(P<0.05,P<0.01);(2)与阴性对照组比较,蔗糖与配伍组可明显增加运动前(P<0.01,P<0.05)、运动后的肌糖原含量(P<0.05)。(3)与阴性对照组比较,试验各组的运动前、后及运动后休息36h血糖差异均无显著性(P>0.05)。结论本研究为蔗糖、蔗糖与西洋参配伍用于保健食品或运动饮料中可延缓疲劳的产生提供了参考数据。     

基于经验模态分解建模法检测肌肉疲劳研究

本文针对表面肌电信号的非平稳特性,采用自回归模型（auto regression,AR）对表面肌电信号进行分析,对短时间内的表面肌电信号的肌肉疲劳迅速做出判定。首先对表面肌电信号进行经验模态分解,得到本征模态函数和趋势项,然后对趋势项进行零化处理,再对本征模态函数分量进行重构处理,重构后的信号可视为均值为零的平稳信号,最后将去势化的信号进行建立自回归模型,采用基于该模型的第一个时变参数（first time-varying parameter of auto regression modle,ARC1）作为检测肌肉疲劳灵敏度的快速指标。用疲劳前后的相关特征值的灵敏度波动比（sensitivity to variability ratio,SVR）来表征肌肉疲劳的灵敏度,较平均功率频率对疲劳反应灵敏度要高。该方法通过表面肌电信号对肌肉疲劳检测时,具有时间短、灵敏度高和将表面肌电信号细微特征信息放大、便于识别的效果等优点。     

高强度有氧运动下的肌肉强度变化分析

研究高强度有氧运动下运动员肌肉强度的变化情况及发生机制。有氧运动是指人体在氧气充分供应的情况下进行的体育锻炼,肌肉指身体肌肉组织和皮下脂肪组织的总称,研究高强度有氧运动下的肌肉强度变化十分重要。采用交叉对比的方法对17名长跑运动员进行高强度有氧运动下的实验。采集运动员的血液测量乳酸含量,利用肌肉拉伸强度检测器测量运动员的肌肉强度变化情况。实验结果表明,在高强度有氧运动的初期,运动员体内的乳酸含量逐渐升高,同时运动员的肌肉强度也有了显著提高(P0.5);在高强度有氧运动的后期至力竭后的恢复期,乳酸的含量逐渐增高,运动员的肌肉强度先是到达最高值,然后逐渐降低,最后低于安静状态时的水平(P0.1),差异显著;说明乳酸在高强度运动中对于肌肉强度的变化起到决定性的作用,同时乳酸积累也是导致肌肉强度下降的主要因素。