Crockett E L, Hazel J R
Department of Zoology, Arizona State University, Tempe 85287-1501.
J Exp Zool. 1995 Feb 15;271(3):190-5. doi: 10.1002/jez.1402710305.
Quantification of cholesterol in biological membranes from a variety of sources is an important step toward understanding cholesterol's roles in membrane function. We extend to biological membranes the fluorometric/enzymatic approach (cholesterol oxidase) to measure cholesterol, originally described for whole cells (Heider and Boyett [1978] J. Lipid Res., 19:514-518; Gamble et al. [1978] J. Lipid Res., 19:1068-1070) and serum (Huang et al. [1975] Clin Chem., 21:1605-1608). This method has a detection limit of 0.3 microgram cholesterol. As revealed by comparison with high-performance liquid chromatography, the fluorometric/enzymatic method with biological membranes is accurate (within 4% and 8% for intestinal and hepatic plasma membranes, respectively). The assay may be completed within 3 to 4 hours and requires neither lipid extraction nor chromatographic techniques. Kinetics of the cholesterol oxidase reaction are membrane-specific, and first-order rate constants (k) are positively correlated with membrane order.
对来自各种来源的生物膜中的胆固醇进行定量，是迈向了解胆固醇在膜功能中作用的重要一步。我们将最初用于全细胞（Heider和Boyett [1978]《脂质研究杂志》，19:514 - 518；Gamble等人 [1978]《脂质研究杂志》，19:1068 - 1070）和血清（Huang等人 [1975]《临床化学》，21:1605 - 1608）的荧光/酶促方法（胆固醇氧化酶）扩展应用于生物膜。该方法的检测限为0.3微克胆固醇。与高效液相色谱法对比显示，用于生物膜的荧光/酶促方法是准确的（对于肠和肝质膜，分别在4%和8%以内）。该测定可在3至4小时内完成，既不需要脂质提取也不需要色谱技术。胆固醇氧化酶反应的动力学是膜特异性的，一级速率常数（k）与膜有序性呈正相关。
