Tsuchiya Hironori, Mizogami Maki, Takakura Ko
Asahi University School of Dentistry, 1851-1 Hozumi, Mizuho, Gifu 501-0296, Japan.
J Chromatogr A. 2005 May 6;1073(1-2):303-8. doi: 10.1016/j.chroma.2004.08.154.
The chromatographic retention and membrane activity relationships of local anesthetics were studied to address the possible mechanisms for structure specificity and inflammation-associated decrease of their effects. Five representative drugs (3 mM for each) were reacted with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine liposomes in 25 mM potassium phosphate buffer (pH 5.9-7.9, containing 100 mM NaCl and 0.1 mM EDTA) for 10 min at 37 degrees C and the membrane fluidity changes were analyzed by measuring fluorescence polarization with 1,6-diphenyl-1,3,5-hexatriene. Their capacity factors were determined on octadecyl-, octyl- and phenyl-bonded silica columns with a mobile phase consisting of 25 mM potassium phosphate buffer (pH 5.9-7.9, containing 100 mM NaCl and 0.1 mM EDTA)-methanol (30:70, v/v) at a flow rate of 1.0 ml/min and at a column temperature of 37 degrees C and diode-array detection. Mepivacaine, prilocaine, lidocaine, ropivacaine and bupivacaine fluidized membranes in increasing order of intensity, which agreed with their clinical potency. The relative degree of membrane fluidization correlated with that of retention on an octadecyl stationary phase more significantly than the other phases. Both membrane-fluidizing effects and capacity factors decreased by lowering the reaction and mobile phase pH, being consistent with the hypothesis that anesthetic potency is reduced in inflammation because of tissue acidity. Reversed-phase liquid chromatography appears to be useful for estimating the structure-specific and pH-dependent membrane-fluidizing effects of local anesthetics.
研究了局部麻醉药的色谱保留与膜活性关系，以探讨其结构特异性及与炎症相关的效应降低的可能机制。将五种代表性药物（每种3 mM）与1,2 - 二棕榈酰 - sn - 甘油 - 3 - 磷酸胆碱脂质体在25 mM磷酸钾缓冲液（pH 5.9 - 7.9，含100 mM NaCl和0.1 mM EDTA）中于37℃反应10分钟，通过用1,6 - 二苯基 - 1,3,5 - 己三烯测量荧光偏振来分析膜流动性变化。在十八烷基、辛基和苯基键合硅胶柱上测定它们的容量因子，流动相由25 mM磷酸钾缓冲液（pH 5.9 - 7.9，含100 mM NaCl和0.1 mM EDTA） - 甲醇（30:70，v/v）组成，流速为1.0 ml/min，柱温为37℃，采用二极管阵列检测。甲哌卡因、丙胺卡因、利多卡因、罗哌卡因和布比卡因使膜流动性增强的程度依次增加，这与其临床效力一致。膜流动性的相对程度与在十八烷基固定相上的保留程度的相关性比在其他固定相上更显著。通过降低反应和流动相的pH值，膜流动性增强效应和容量因子均降低，这与炎症时由于组织酸度导致麻醉效力降低的假说一致。反相液相色谱似乎可用于评估局部麻醉药的结构特异性和pH依赖性膜流动性增强效应。
