Kaminoh Y, Tashiro C, Kamaya H, Ueda I
Department of Anesthesia, University of Utah School of Medicine, Salt Lake City.
Biochim Biophys Acta. 1988 Dec 22;946(2):215-20. doi: 10.1016/0005-2736(88)90395-1.
The anesthetic-induced depression of the main phase-transition temperature of phospholipid membranes is often analyzed according to the van't Hoff model on the freezing point depression. In this procedure, zero interaction between anesthetics and solid-gel membranes is assumed. Nevertheless, anesthetics bind to solid-gel membranes to a significant degree. It is necessary to analyze the difference in the anesthetic binding between the liquid-crystal and solid-gel membranes to probe the anesthetic action on the lipid membranes. This article describes a theory to estimate the anesthetic binding to each state at the phase-transition temperature. The equations derived here reveal the relation between the partition coefficients of anesthetics and the anesthetic effects on the transition characters: the change in the transition temperature, and the broadening of transition. The theory revealed that the width of transition temperature is determined primarily by the membrane/buffer partition coefficients of anesthetics. Our previous data on the local anesthetic action on the transition temperature of the dipalmitoylphosphatidylcholine vesicle membrane (Ueda, I., Tashiro, C. and Arakawa, K. (1977) Anesthesiology 46, 327-332) are analyzed by this method. The numerical values for the partition of local anesthetics into the liquid-crystal and solid-gel dipalmitoyl-phosphatidylcholine vesicle membranes at the phase-transition temperature are: procaine 8.0 x 10(3) and 4.7 x 10(3), lidocaine, 3.7 x 10(3) and 2.3 x 10(3), bupivacaine 4.1 x 10(4), and 2.6 x 10(4), and tetracaine 7.3 x 10(4) and 4.7 x 10(4), respectively.
麻醉剂引起的磷脂膜主相变温度降低通常根据范特霍夫冰点降低模型进行分析。在此过程中，假定麻醉剂与固体 - 凝胶膜之间不存在相互作用。然而，麻醉剂会在很大程度上与固体 - 凝胶膜结合。有必要分析液晶膜和固体 - 凝胶膜之间麻醉剂结合的差异，以探究麻醉剂对脂质膜的作用。本文描述了一种理论，用于估计在相变温度下麻醉剂与每种状态的结合情况。此处推导的方程揭示了麻醉剂分配系数与麻醉剂对转变特性（转变温度的变化和转变的展宽）的影响之间的关系。该理论表明，转变温度的宽度主要由麻醉剂的膜/缓冲液分配系数决定。我们之前关于局部麻醉剂对二棕榈酰磷脂酰胆碱囊泡膜转变温度作用的数据（上田，I.，田代，C.和荒川，K.（1977年）《麻醉学》46卷，327 - 332页）通过该方法进行了分析。在相变温度下，局部麻醉剂在液晶态和固体 - 凝胶态二棕榈酰磷脂酰胆碱囊泡膜中的分配数值分别为：普鲁卡因8.0×10³和4.7×10³，利多卡因3.7×10³和2.3×10³，布比卡因4.1×10⁴和2.6×10⁴，以及丁卡因7.3×10⁴和4.7×10⁴。
