Tamura K, Kaminoh Y, Kamaya H, Ueda I
Department of Anesthesia, University of Utah College of Medicine, Salt Lake City.
Biochim Biophys Acta. 1991 Jul 22;1066(2):219-24. doi: 10.1016/0005-2736(91)90189-f.
The combined effects of high pressure (up to 300 bar) and a homologous series of 1-alkanols (ethanol C2 to 1-tridecanol C13) were studied on the main phase-transition temperature of dipalmitoylphosphatidylcholine (DPPC) vesicle membranes. It is known that short-chain alkanols depress and long-chain alkanols elevate the main transition temperature. The crossover from depression to elevation occurs at the carbon-chain length about C10-C12 in DPPC vesicle membranes coinciding with the cutoff chain-length where anesthetic potency suddenly disappears. Alkanols shorter than C8 linearly decreased the transition temperature and high pressure antagonized the temperature depression. Alkanols longer than C10 showed biphasic dose-response curves. High pressure enhanced the biphasic response. In addition, alkanols longer than the cutoff length depressed the transition temperature under high pressure at the low concentration range. These non-anesthetic alkanols may manifest anesthetic potency under high pressure. At higher concentrations, the temperature elevatory effect was accentuated by pressure. This biphasic effect of long-chain alkanols is not related to the 'interdigitation' associated with short-chain alkanols. The increment of the transition temperature by pressure was 0.0242 K bar-1 in the absence of alkanols. The volume change of the transition was estimated to be 27.7 cm3 mol-1. This value stayed constant to the limit of the present study of 300 bar.
研究了高压（高达300巴）与一系列同系1-链烷醇（从乙醇C2到1-十三烷醇C13）对二棕榈酰磷脂酰胆碱（DPPC）囊泡膜主要相变温度的综合影响。已知短链链烷醇会降低而长链链烷醇会升高主要相变温度。在DPPC囊泡膜中，从降低到升高的转变发生在碳链长度约为C10 - C12处，这与麻醉效力突然消失的截止链长一致。短于C8的链烷醇线性降低转变温度，高压可对抗温度降低。长于C10的链烷醇呈现双相剂量反应曲线。高压增强了双相反应。此外，长于截止长度的链烷醇在低浓度范围内于高压下会降低转变温度。这些非麻醉性链烷醇在高压下可能表现出麻醉效力。在较高浓度下，压力会加剧温度升高效应。长链链烷醇的这种双相效应与短链链烷醇相关的“交叉指状排列”无关。在不存在链烷醇的情况下，压力导致的转变温度增量为每巴0.0242 K。转变的体积变化估计为27.7 cm³·mol⁻¹。在本研究300巴的极限范围内，该值保持恒定。
