Singlet-oxygen generation from liposomes: A comparison of 6 beta-cholesterol hydroperoxide formation with predictions from a one-dimensional model of singlet-oxygen diffusion and quenching
Singlet-oxygen generation from liposomes: A comparison of 6 beta-cholesterol hydroperoxide formation with predictions from a one-dimensional model of singlet-oxygen diffusion and quenching
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DOI：
10.1111/j.1751-1097.1996.tb03071.x
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发表时间：
1996-04-01
影响因子：
3.3
通讯作者：
Kanofsky, JR
中科院分区：
文献类型：
--
作者：
Fu, YX;Sima, PD;Kanofsky, JR
我们测量了 6 β-胆固醇氢过氧化物 (6 β-CHP)，一种特定的单线态氧 (O-2((1) Delta(g))) 产品，在含有胆固醇和锌酞菁 (ZnPC) 的单层二肉豆蔻酰 1-α-磷脂酰胆碱脂质体的照射过程中，脂质体大小、疏水性 (O-2((1) Delta(g))) 猝灭剂的影响， β-胡萝卜素和亲水性 O-2((1) Delta(g)) 猝灭剂对 6 β-CHP 形成量的影响根据 O-2((1) Delta(g)) 猝灭和扩散的一维模型进行测定和解释。该模型正确预测 (1) 6 β-CHP 的量随着脂质体尺寸的增加而增加，(2) β-胡萝卜素在减少 6 β-CHP 形成方面更有效。 400 mn 直径的脂质体比 100 mn 直径的脂质体更有效，并且 (3) 亲水性猝灭剂水在大脂质体中也比在小脂质体中更有效。疏水性猝灭剂 β-胡萝卜素在减少 6 β-CHP 的形成方面比减少 1270 mn O-2((1) Delta(g)) 排放更有效。发现这种差异是由于存在的尺寸分布造成的由于在粒径分布较窄的脂质体制剂中，6 β-CHP 数据与 1270 mn 发射数据之间的差异要小得多。当存在显着的粒径分布时，大直径脂质体对 6 β-CHP 数据的权重更大，而小直径脂质体对 1270 mn 发射数据的权重更大。
We measured 6 beta-cholesterol hydroperoxide (6 beta-CHP), a specific singlet-oxygen (O-2((1) Delta(g))) product, during irradiation of unilamellar dimyristoyl 1-alpha-phosphatidylcholine liposomes containing cholesterol and zinc phthalocyanine (ZnPC), The effects of liposome size, the hydrophobic (O-2((1) Delta(g))) quencher, beta-carotene, and hydrophilic O-2((1) Delta(g)) quenchers upon the amount of 6 beta-CHP formed were determined and interpreted in terms of a one dimensional model of O-2((1) Delta(g)) quenching and diffusion, The model correctly predicted (1) that the amount of 6 beta-CHP was increased with increasing liposome size, (2) that beta-carotene was more effective at reducing 6 beta-CHP formation in 400 mn diameter liposomes than 100 mn diameter liposomes and (3) that the hydrophilic quencher, water, was also more effective in large liposomes than in small liposomes.The hydrophobic quencher, beta-carotene, was more effective at reducing the formation of 6 beta-CHP than at reducing the 1270 mn O-2((1) Delta(g)) emission, This difference was found to be due to the size distribution present in the liposome preparations because the difference between the 6 beta-CHP data and the 1270 mn emission data was much smaller in liposome preparations with a narrow size distribution, When a significant size distribution was present, the 6 beta-CHP data were weighted more heavily with large-diameter liposomes, while the 1270 mn emission data were weighted more heavily with small-diameter liposomes.