The Protective Effect Of Galanin On Injured Hippocampal Cells In Vitro

Galanin (GAL) is a 29 - 30 amino-acid neuropeptide. It is spread throughout the central nervous system. Recently, many evidences showed that galanin may be concerned with nerve injury reaction, nerve regeneration and nerve repairationo This experiment investigates the injury effect caused by H₂O₂ and glutamate and the protective effect of galanin on hippocampal nerve cells.The experiment is made up of three parts. First, neonatal (one- to two-day-old) SD rats were selected, hippocampus of their brain were got and the hippocampal nerve cell cultures were obtained. Then, the culture was treated with cytosine arabinoside (Ara-C) and the purified hippocampal nerve cells were received. The immunohistochemical ABC method was used to identify hippocampal nerve cells and galanin positive cells. The RT-PCR analysis was used to detect mRNAs for GAL's three receptors. Second, two kinds of damage model were made. Hippocampal nerve cells were treated with a series concentration of H₂O₂ and glutamate. MTT analysis was used to detect the survival rate of hippocampal nerve cells. Third, the effect of GAL on hippocampal nerve cells were detected. Observe the effect of GAL, GAL agonist GALl-11 and GAL2-11. Use GAL antagonist M35 to block the effect of GAL, GAL1-11 and GAL2-11. And use Fura-2/AM to detect the intracellular calcium level. The followings are the results of this study:1) By the above methods of isolation and purification, hippocampal nerve cells, which can grow stably in vitro, were successfully obtained. In vitro, hippocampal nerve cells express GAL protein. Furthermore, the mRNA of GalR2 and GalR3 were detected, but the mRNA of GalR1 was not.2) Except 0.2mM, every concentrations of H₂O₂ decrease the survival rate significantly. And except 0.3mM, every concentrations of Glu decrease the survival rate significantly. With the increases of the concentration of H₂O₂ and Glu the survival rate is becoming lower and lower. GAL can decrease the intracellular calcium level in hippocampal nerve cells damaged by H₂O₂.