The Expression Change Of Neuropeptide Y MRNA Of Cerebral Tissues In Rat Cerebral Vasospasm Induced By Subarachnoid Hemorrhage

The expression change of neuropeptide Y mRNA of cerebral tissues in rats cerebral vasospam induced by subarachnoid hemorrhage Master Candidate: Lin Jing-ming Supervisior: Professor Song Lie-chang The lab for molecule pharmacoiogy ,The department of hygiene The First Militaiy Medicial University GUANGZHOU 510515 ABSTRACT Background Cerebral vasospasm (CVS) induced by subarachnoid hemorrhage can result in the insufficient blood supply of cerebral vascular and cerebral ischemia, which will damage the function of brain. CVS is the most serious and common complication of SAH. Its rate of disability and rate of death are rather high. It has been argued which substances produce CVS. Several substances are considered to involve to the process of CVS in SAH. Up to date, there is not effective method to treat CVS. It is necessary to further study its pathogenesis. In recent two decades, neuropeptide Y (NPY) was discovered to take part in many physiological process which induded strong contraction reaction of blood vessel. There existes NPY in CSF and plasma of mammal. It is believed that the increasing NPY in CSF and plasma is the most importance factor causing CVS after SAH. This project is to establish a SAM model in rats, then to examine its pathophysiological changes and the expression of NPY in the early stage of SAIl. Methods 1. a. To establish the SAH model in rats by injecting autologous blood into subarachnoid space. b. To measure the regional cerebral blood flow (rCBF) and some biochemical items in the model. c. To inspect the microvascular states of cerebral vasospasm by scanning electron microscopy (SEM). 2. To measure the parameters of hemorrheology in SAH. 3. To investigate the level expression of NPY in rat抯 brain in SAH by immunohis chemical technique. 4. To investigate the expression of NPY mRNA in CVS of SAM by RT-PCR. 4 Results 1. The SAH model in rats was established successfully and cerebral vasospasm states at the different times were observed by SEM. 2. There was a biphasic change of rCBF in the early stage of SAl-I in rats, in which the first decrease might be due to the stress reaction and the second decrease might be due to CVS. The change of rCBF reflected the process of cvS. 3. In hemorrheology, rl~, ri b, PFC, HCT, VAI and TK before SAIL were higher than those after SAIL. But the couection rate of platelets before SAIL was lower than that after SAl-I 4. After SAH, the number of cells with positive reactions to NPY antibody was increased significantly. 5. The expression level of NPY mRNA was higher in SAH than in the contral group. Conclusions In the rat pathological model, the expression of NPY niRNA upgraded in cerebral cortex, corpus striatum, hypothalamus after CVS induced by SAIL. The raising level of NPY might aggravate or the regional cerebral vasospasm or make the vasospasm prolonged. Innovative points 1. We firstly reported that the expression of NPY mRNA was upgraded and the level of NPY was raised in cerebral cortex, corpus striatum, hypothalams after CVS induced in the rats SAIL model, and firstly pointed out that the vicious circle was one of causalities that...