NEUROTROPHIC ACTIVITY IN BRAIN WOUND TISSUE EXTRACT AND THE ORIGIN OF THE ACTIVE FACTORS / 解剖学报

ABSTRACT

Bilateral ablation of the cerebral parietal cortex in adult rats was performed. After appropriate days, the tissue surrounding the wound was removed and the brain wound tissue extract (EWTE) was prepared. Newborn rat cerebral cortical neurons were used as a culture model to test the neuronotrophic factors (NTFs) and neuritepromoting factors (NPFs) in EWTE. In order to investigate the origin of above mentioned factors whether related to the macrophages which appeared in the brain wound region at early stage, we designed to culture macrophages and collected the macrophage conditioned medium (M?CM) to measure their NTF and NPF activities for cultured cerebral cortical neurons. On the other hand, we also observed the effect of EWTE and M?CM on PC 12 (phehrmytema) cells and further studied the action of NPFs. Cur experimental results show that EWTE and M?CM contained NTFs and NPFs for cultured cerebral cortical neurons. These factors appeared in EWTE at 4 days post-lesion, with maximal level of their activities reached between 5 and 6 days post-lesion and there was another peak of NPF activity at 9 days post-lesion, until 13 days post-lesion also detected their activities. The NTF activity in M?CM was lower than that in BWTE, in contrast, the NPF activity in M?CM was higher than that in BWTE. There was NPF activity to PC 12 cells in BWTE and M?CM. According to the experimental assays, we suppose that the neurotrophic factors in BWTE mainly come from the macrophages which appear in the lesion site at early stage of injured brain, subsequently, it may relate to the astrocytes. The components of these factors may be complexity and multiplicity that remain to be solved.