NMR Dynamic Studies in Living Systems

IntroductionApplications of nuclear magnetic resonance(NMR) spectroscopy in the study of living systemsrepresent an ever-expanding area of researchactively pursued in many universities and researchinstitutions[1 ] .The interestin studying living cellswith NMR techniques stemmed from the exchangeexperiments of human blood cells in D2 Operformed by Odeblad et al.in the mid-1 95 0 s[2 ] .Continued interest in defining and explaining theproperties of water in biological tissue from themid-1 96…     

In vivo Dynamic Studies of Brain Metabolism

Nuclear magnetic resonance （NMR） can noninvasively monitor intracellular concentrations and kinetic properties of numerous inorganic and organic compounds. A ^31p NMR surface coil was used in vivo to dynamically measure phosphocreatine （PCr）, adenosine triphosphate （ATP）, and intracellular inorganic phosphate （Pi） levels in mouse brain during ischemia-reperfusion to study the damage of cerebral tissues caused by ischemia and effects of herbs on cerebral energy metabolism during ischemia-reperfusion. The study provides dynamic brain energy metabolism data during different periods. The data show that some herbs more rapidly increase the PCr level during the recovery phase than in the control group.     

Effect of Salvianolic Acid B on Mitochondrial Function of CerebralIschemia in Mice

The effects of salvianolic acid B (SalB) on the mitochondrial membrane potential (MMP), calcium, and apoptosis of neurons with cerebral ischemia in mice were investigated using an acute cerebral ischemia model established by ligating the bilateral common carotid arteries in mice. The MMP, the intracellular calcium concentration, and the apoptosis rate of cortical neurons were measured at 6 min, 12 min, 18 min, 24 min, and 30 min after cerebral ischemia by a flow cytometer. The experiments show that SalB increases the MMP and reduces the intracellular calcium and the apoptosis rate at different stages of the cerebral ischemia in mice. The results show that the protective mechanism of SalB on cerebral ischemia enhances the MMP and maintains intracellular calcium homeostasis.     

应用￣(31)P-NMR研究跨膜多肽IS4对脂质体的影响

ＩＳ４是鼠脑钠离子通道蛋白第一结构域中保守性跨膜多肽序列中的第４个跨膜片段。ＩＳ４插入膜之后会引起膜的结构和功能的变化。通过３１Ｐ－ＮＭＲ技术可研究磷脂分子在不同条件下除了形成脂双层结构外，还可以形成多种结构。本文利用３１Ｐ－ＮＭＲ峰形的改变来研究ＩＳ４对脂质体结构的影响。实验表明：ＩＳ４能够抑制由于温度的升高以及由于加Ｃａ２＋使其由双层至非双层的转变，从而使脂双层结构更加稳定。     

Interaction of Divalent Metal Ions with the Adenosine Triphosphate Measured Using Nuclear Magnetic Resonance

Theinteractionofadenosinetriphosphatewithdivalentmetalionsisimportantinbiochemicalfunctions.TheintracellularfreeMg2 canbeestimated[1]byseparatingtheα-andβ-phosphatepeaksoftheATPNMR31PspectrumandbyknowingtheMgATPdissociationconstant.TheneedfordivalentmetalionsforallenzymaticreactionsinvolvingATPiswellknown,buttheroleofthemetalionsisnotclear[2].ThisstudywasconductedtoobtaininformationconcerningchangesinthestructureofadenosinetriphosphatecausedbyinteractionwithdivalentmetalionsMg2 ,Ca2 ,…     

Thermal Transition of Ribonuclease A Observed Using Proton Nuclear Magnetic Resonance

IntroductionBovine pancreatic ribonuclease A ( RNase A) ,asingle- domain protein that has four disulfidebonds,has played a crucial role in studies ofprotein structure,folding and enzyme catalysis.We propose extending these studies by imageanalysis through the use of nuclear magneticresonance ( NMR) spectroscopy,which has theadvantage of direct,continuous,dynamic,nondestructive,and quantitative monitoring.Absorbance measurements at 2 86nm/2 87nm( UV difference spectroscopy) have beentraditi…     

大鼠离体心脏缺血预处理的核磁共振研究

缺血预处理(IPC)是一种肌体对长时间缺血产生耐受性的处理技术.应用核磁共振表面线圈技术获得大鼠心肌在灌流的不同阶段的31P谱,可以从能量代谢的角度对缺血/再灌注心脏进行连续、动态、无损伤的检测,从含磷代谢物的转化对缺血预处理产生作用的机理进行研究.实验结果显示,缺血预处理的保护作用并不是通过有利于心肌内ATP和PCr(磷酸肌酸)恢复的水平来体现的,而是在缺血期通过缓和pHi(胞内pH)值的突然变化和ATP的大量消耗以及通过pHi值和ATP的尽快恢复来减轻心肌组织结构在缺血期产生的严重损伤,从而有利于再灌注时心肌功能的恢复.     

NMR Study of Damage on Isolated Perfused Rat Heart Exposed to Ischemia and Hypoxia

IntroductionMyocardial ischemia is the most common andprimary cause of myocardium damage. A rapidrestoration of the heartblood supply after injury isvery important for retaining its function.However,after a certain period of time,resumingthe blood supply may aggravate the damage to thecardiac muscle. Therefore,the mechanisms ofmyocardial ischemia and reperfusion damage mustbe studied to provide important data to reduce orprevent reperfusion damage in clinical treatmentofischemic heart diseases…     

NMR Analysis of the Structure of Leucine Enkephalin in Solution

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In Vivo Study of Brain Metabolism Using Nuclear Magnetic Resonance

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