Petrov A M, Kasimov M R, Giniatullin A R, Zefirov A L
Ross Fiziol Zh Im I M Sechenova. 2013 Feb;99(2):245-60.
In experiments on frog (Rana ridibunda) neuromuscular junction the influence of cholesterol oxidation on the presynaptic vesicular cycle was investigated. Application of cholesterol oxidase (1 u. a.) during 1/2 hour led to the oxidation of - 0.007 mg cholesterol per 1 g tissue and reduced stability of lipid rafts in the nerve terminals. Using electrophysiological techniques it was shown that the cholesterol oxidation decreases the evoked neurotransmitter release. In experiments with fluorescent FM-dyes the depression of the synaptic vesicles exo-endocytosis and the dispersion of synaptic vesicles clusters were revealed. Comparative analysis of electrophysiological and optical data, as well as experiments with water soluble quencher of FM-dye indicated the possibility of some neurotransmitter release by "kiss-and-run" pathway, when short-lived fusion pore is formed. It was concluded that cholesterol oxidation inhibit evoked exocytosis, and also synaptic vesicle delivery from reserve pool to cites of exocytosis probably by break of the clusterization. Perhaps the synaptic vesicles of recycling pool release the neurotransmitter using the kiss-and-run mechanism.
在对青蛙（食用蛙）神经肌肉接头进行的实验中，研究了胆固醇氧化对突触前囊泡循环的影响。在半小时内应用胆固醇氧化酶（1 单位活性）导致每 1 克组织中 -0.007 毫克胆固醇被氧化，并降低了神经末梢中脂筏的稳定性。使用电生理技术表明，胆固醇氧化会减少诱发的神经递质释放。在使用荧光 FM 染料的实验中，发现突触囊泡的胞吐 - 内吞作用受到抑制，并且突触囊泡簇发生分散。对电生理和光学数据的比较分析，以及使用 FM 染料水溶性淬灭剂的实验表明，当形成短暂的融合孔时，存在一些神经递质通过“亲吻 - 逃离”途径释放的可能性。得出的结论是，胆固醇氧化抑制诱发的胞吐作用，并且可能通过破坏聚集作用抑制突触囊泡从储备池转运到胞吐位点。也许再循环池的突触囊泡使用“亲吻 - 逃离”机制释放神经递质。
