Experimental Studies On The Role Of P38MAPK And Its Mechanism In Cerebral Vasospasm After Subarachnoid Hemorrhage

Part one: The expression of p38MAPK in the basilar artery walls after subarachnoid hemorrhage in rabbitsObjective We investigated the expression of phosphorylated p38 mitogen- activated protein kinase (MAPK) in the rabbits basilar arteries to clarify the role of this stress kinase on the development of cerebral vasospasm(CVS) after experimental subarachnoid hemorrhage(SAH). Methods Thirty-five rabbits were divided into Normal, Control(normal saline was injected into the cisterna magna ),SAH3d, SAH5d, SAH7d, SAH10d, and SAH14d seven groups .SAH was produced by injecting autologous arterial blood into the cisterna magna twice at 48-hour intervals in rabbits. Laser-doppler flowmetery (LDF) was used to measure regional cerebral blood flow(rCBF) , the morphological changes of basilar arteries were studied with angiography, light and transmission electron microscopy after experimental SAH, and the expression of phosphorylated p38 MAPK in the vascular wall was examined with an immunohistochemical technique. Results rCBF detected with LDF decreased as early as on day 3 after SAH and partly increased on Day 5 , but it was still abnormal on day 7 when compared with Normal and Control group(P<0.05),then came back on day 10 after SAH. Angiographic vasospasm began on day 3 and peaked on day 7. Light and transmission electron microscopy investigation indicated that the pathological changes including arterial norrowing , thickness of arterial wall,degeneration of endothelial cells and smooth muscle cells started on day 3 , such changes progressed with time and obviously on day 5 and day 7 ,especilly on day 7, the changes began to relieve on day 10 after SAH. The upregulation of phosphorylated p38 was detected in the vascular wall on day 3, became more stronger on day 5 and remained enhanced on day 7, and decreased on day 10 after SAH. Conclusion This study demonstrates that the rabbit...