Hazzard J H, Gorga J C, Caughey W S
Arch Biochem Biophys. 1985 Aug 1;240(2):747-56. doi: 10.1016/0003-9861(85)90083-9.
The presence of molecules of the general anesthetic nitrous oxide (N2O) in oils, esters, proteins, red cells, cream, lipid vesicles, and brain tissue upon exposure to the gas was observed by infrared spectroscopy. Analysis of the N-N-O antisymmetric stretch band reveals a distribution of N2O molecules among several sites of differing polarity in these solutions and tissues. The sensitivity of the band intensity and frequency to the number and strength of the dipoles in the solvating molecules is demonstrated by the resolution of N2O-ester and N2O-alkane interactions in acetic acid ethyl ester and oleic acid methyl ester. In all aqueous solutions and in all tissues a population of N2O molecules in water is observed. At least two sites of N2O-protein interaction are observed in purified hemoglobin A and packed red cells; multiple N2O sites may also be present in bovine serum albumin. Two sites of N2O-lipid interaction are observed in whipping cream and in an aqueous suspension of phosphatidylcholine vesicles. The sites providing the least polar immediate environment to N2O in hemoglobin, cream, and vesicles give similar band frequencies to those found in pure alkane solvents. Infrared spectra of bovine brain tissue, upon exposure to N2O, show N2O molecules present in water and in two less-polar environments. Analysis of spectra of N2O in cerebellum tissue removed from a dog under halothane-N2O anesthesia reveals, in addition to N2O in water, a single population of N2O molecules in an alkane-like environment. Infrared spectroscopy provides a unique means of probing the structure of the environment of N2O and should prove useful in correlating anesthetic potency with anesthetic environment under physiological conditions.
通过红外光谱法观察到，在接触气体后，油类、酯类、蛋白质、红细胞、乳膏、脂质囊泡和脑组织中存在全身麻醉剂一氧化二氮（N₂O）分子。对N-N-O反对称伸缩带的分析揭示了N₂O分子在这些溶液和组织中不同极性的几个位点之间的分布。通过乙酸乙酯和油酸甲酯中N₂O-酯和N₂O-烷烃相互作用的解析，证明了该谱带强度和频率对溶剂化分子中偶极子数量和强度的敏感性。在所有水溶液和所有组织中都观察到水中存在一群N₂O分子。在纯化的血红蛋白A和 packed红细胞中观察到至少两个N₂O-蛋白质相互作用位点；牛血清白蛋白中也可能存在多个N₂O位点。在搅打奶油和磷脂酰胆碱囊泡的水悬浮液中观察到两个N₂O-脂质相互作用位点。在血红蛋白、乳膏和囊泡中为N₂O提供极性最小的直接环境的位点，其谱带频率与纯烷烃溶剂中的相似。暴露于N₂O后，牛脑组织的红外光谱显示N₂O分子存在于水中和两个极性较小的环境中。对在氟烷-N₂O麻醉下从狗身上取出的小脑组织中N₂O光谱的分析表明，除了水中的N₂O外，在类似烷烃的环境中还有一群单一的N₂O分子。红外光谱法提供了一种独特的方法来探测N₂O环境的结构，并且应该证明在将麻醉效力与生理条件下的麻醉环境相关联方面是有用的。
