褪黑激素对小鼠脑细胞膜流动性及丙二醛含量的影响(英文)

Effects of melatonin on membrane fluidity and malondialdehyde content in mouse brain cell

以荧光染料ＤＰＨ 负载脑皮层突触体或细胞， 用ＭＰＦ－４ 荧光分光光度计检测膜流动性；ＴＢＡ 比色法测定丙二醛（ＭＤＡ）含量，观察褪黑激素（ＭＴ）对小鼠脑细胞膜流动性和ＭＤＡ 含量的影响． 结果显示ＭＴ（１ 或２０ ｍ ｇ·Ｌ－ １饮水中口服３个月，最后１ 个月再ｉｐ ＭＴ ０．５ 或２．０ ｍ ｇ·ｋｇ－ １·ｄ－ １ ）能够提高老年小鼠脑细胞膜的流动性，ＭＴ０．０１－ １．０ μｍ ｏｌ·Ｌ－ １拮抗氧化剂诱发的分离新生小鼠脑细胞膜流动性下降及部分拮抗其ＭＤＡ 含量增加． 结果说明，作为一种体内抗氧化激素， ＭＴ提高脑细胞膜流动性，降低脑细胞内ＭＤＡ 含量， 从而对神经元有保护作用，是其重要的抗衰老机理之一．

The effects of melatonin (MT) on cortical synaptosomal membrane fluidity in old mice, and the reduction of membrane fluidity and the increase in malondialdehyde (MDA) content induced by oxidants in isolated brain cells of neonatal mouse were studied respectively. The results showed that MT (1, 20 mg·L -1 po for 3 months and additional 0.5, 2.0 mg·kg -1 ip, respectively, once a day in the last month) increased the membrane fluidity 〔ρ values from 0.311±0.029 (control) to 0.273±0.009 and 0.255±0.018 respectively〕 in old mouse cerebral cortex synaptosomes, and MT 0.01-1.0 μmol·L -1 antagonized the reduction of oxidant reduced membrane fluidity 〔ρ values from 0.2826±0.0018 (oxidant only) to 0.2444±0.0081 (1.0 μmol·L -1 MT)〕, and the increase in MDA content 〔(72.6±1.9) nmol·g -1 (oxidant only) to (63.6±3.8) nmol·g -1 (1.0 μmol·L -1 MT)〕 in isolated newborn mouse brain cells(2×10 6 L -1 ). It is concluded that MT increases the membrane fluidity, decreases the MDA content of brain cells and protects neurons, which are probably important antiaging mechanisms of MT.