Yamada K, Kinoshita A, Kohmura E, Kataoka K, Sakaguchi T, Taneda M, Kuroda R, Hayakawa T
Department of Neurosurgery, Osaka University Medical School, Japan.
Neurol Res. 1992 Jun;14(3):267-72. doi: 10.1080/01616412.1992.11740068.
In the rat model of middle cerebral artery (MCA) occlusion, axons originating from the ipsilateral cortical and thalamic neurons are injured by ischaemia. The cortical neurons survive thereafter without retrograde degeneration, but thalamic neurons slowly die because of retrograde degeneration. The fate of these two neurons is remarkably different and may be related to neurotrophic activity induced by ischaemia. We detected ischaemia-related neurotrophic activity, and partially purified the factor. Tissue samples were obtained from the cortex adjacent to the infarction and contralateral corresponding site at 4, 8 and 12 days after occlusion of the MCA. They were homogenated with a culture medium and ultracentrifuged. The supernatant was obtained and used for neurotrophic assay. Foetal cortical neurons were obtained from 17 days rat embryo and cultured. Neurotrophic activity was assayed by applying tissue extract to the culture medium. Application of periischaemic cortical extract obtained at 8 and 12 days after ischaemia improved neuronal survival by 50% and 200% as compared to contralateral cortical extract, respectively. The activity was not detectable at 4 days after ischaemia. The neurotrophic activity disappeared by heating the extract at 90 degrees C for 10 min. We fractionated the extract by saturated ammonium sulphate precipitation, followed by gel-filtered with Superose 12 column. The neurotrophic activity was detected in the precipitation of 30 to 60% saturation fraction of ammonium sulphate. With gel-filtration we separated neurotrophic activity in several fractions, which included marker proteins of 8, 22 and 30 kilodaltons. The activities were only detected in the lesioned side but not in the contralateral side.(ABSTRACT TRUNCATED AT 250 WORDS)
在大脑中动脉（MCA）闭塞的大鼠模型中，源自同侧皮质和丘脑神经元的轴突会因缺血而受损。此后，皮质神经元存活下来，没有发生逆行性变性，但丘脑神经元由于逆行性变性而逐渐死亡。这两种神经元的命运明显不同，可能与缺血诱导的神经营养活性有关。我们检测了缺血相关的神经营养活性，并对该因子进行了部分纯化。在MCA闭塞后4天、8天和12天，从梗死灶附近的皮质以及对侧相应部位获取组织样本。将它们与培养基匀浆并进行超速离心。获取上清液并用于神经营养测定。从17天龄的大鼠胚胎中获取胎脑皮质神经元并进行培养。通过将组织提取物应用于培养基来测定神经营养活性。与对侧皮质提取物相比，缺血后8天和12天获取的缺血周围皮质提取物分别使神经元存活率提高了50%和200%。缺血后4天未检测到该活性。将提取物在90摄氏度加热10分钟后，神经营养活性消失。我们通过饱和硫酸铵沉淀对提取物进行分级分离，随后用Superose 12柱进行凝胶过滤。在硫酸铵饱和度为30%至60%的沉淀部分中检测到神经营养活性。通过凝胶过滤，我们在几个级分中分离出了神经营养活性，其中包括8、22和30千道尔顿的标记蛋白。这些活性仅在损伤侧检测到，而在对侧未检测到。（摘要截短至250字）
