A Novel Animal Model for Subarachnoid Hemorrhage in Rabbits - Pathology due to Hemorrhage
The Pathophysiological course of subarachnoid hemorrhage (SAH) is not completely understood, such as how and why blood or its lysate can influence the brain. Although many SAH animal models have previously been reported, none are suitable for research in this field. The aim of the present study was to establish such an animal model. Twenty New Zealand rabbits were divided into two groups, a control group and a SAH group (n=10). Blood was lysed using an in vitro freeze-thaw method. After anesthesia, 0.9 ml of cerebrospinal fluid was drawn from both groups. An identical volume of heparinized hemolysate was then slowly injected into the cisterna magna of the SAH group animals. Control group animals while the control group received heparinized isotonic sodium chloride solution. Forty-eight hours post-injection, samples were excised after perfusion fixation for further determinations. The degree of cerebral vasospasm was evaluated by measuring the cross-sectional area of the basilar arterial lumen, and brain damage was examined by TUNEL staining. Weight, blood pressure and saturation of blood oxygen showed no statistical differences between groups. The cross-sectional area of the arterial lumen in the SAH group was roundly 0.402 mm2, which was statistically the same as that for the control group (0.435 mm2). The apoptosis index for the SAH group was significantly higher than that for the control group. Taken together, our results show that this model is effective in reproducing the influence of blood on the brain after SAH and, at the same time, strictly excludes influences on the brain by other factors. Thus, this model can effectively be applied to investigate blood-related neuropathophysiology following SAH.