Barrier L, Tallineau C, Fauconneau B, Piriou A
Institut de Recherche sur les Xénobiotiques, Poitiers.
C R Seances Soc Biol Fil. 1995;189(3):419-28.
The aim of this study was to determine: 1) the source of Thiobarbituric Reactive Substances (TBARS) spontaneously produced during rat brain homogenate incubation; 2) the cellular components involved; 3) the reason why brain and liver homogenates did not have the same behaviour. Measurements of TBARS, Polyunsaturated Fatty Acids (PUFAs), aldehydes coming from PUFAS breakdown, vitamin E and Schiff's bases levels were performed on brain and liver homogenates, membrane fractions (Mb) and medium containing soluble cytoplasmic components (CS). Mb and CS were prepared by differential centrifugation. Brain homogenate incubation, contrary to liver homogenate, led to an increase in TBARS amount, while PUFAS, aldehydes and vitamin E levels remained unchanged. No TBARS accumulation arose when Mb or CS were separately incubated. However, it was of interest to note that liver or brain incubation of Mb with CS led to an overproduction of TBARS. These results suggested that spontaneous oxidation of brain homogenate was not due to lipid peroxidation. On the other hand, the fact that, contrary to the liver homogenate, liver Mb incubated with CS led to an increase in TBARS level, supports the idea that a "protective agent" was eliminated during centrifugation. It can be speculated that this "agent" is not effective in the brain.
1）大鼠脑匀浆孵育过程中自发产生的硫代巴比妥酸反应性物质（TBARS）的来源；2）涉及的细胞成分；3）脑和肝匀浆表现不同的原因。对脑和肝匀浆、膜组分（Mb）以及含有可溶性细胞质成分的培养基（CS）进行了TBARS、多不饱和脂肪酸（PUFA）、PUFA分解产生的醛、维生素E和席夫碱水平的测定。Mb和CS通过差速离心制备。与肝匀浆不同，脑匀浆孵育导致TBARS量增加，而PUFA、醛和维生素E水平保持不变。当分别孵育Mb或CS时，未出现TBARS积累。然而，值得注意的是，Mb与CS一起进行肝或脑孵育会导致TBARS过量产生。这些结果表明，脑匀浆的自发氧化并非由于脂质过氧化。另一方面，与肝匀浆不同，肝Mb与CS一起孵育会导致TBARS水平升高，这一事实支持了一种观点，即一种“保护剂”在离心过程中被去除。可以推测，这种“保护剂”在脑中无效。
