Blocking cerebral lymphatic drainage deteriorates cerebral oxidative injury in rats with subarachnoid hemorrhage

Substances and fluid in the brain and subarachnoid spaces may be drained into extracranial lymphatics. This study aimed to investigate the possible role of cerebral lymphatic drainage in the process of cerebral injury following subarachnoid hemorrhage (SAH). Wistar rats were divided into non-SAH, SAH, and SAH plus cervical lymphatic blockage (SAH + CLB) groups. Autologous arterial hemolysate was injected into rats' cisterna magna to induce SAH. At time of 24 and 72 h after SAH, the rats were sacrificed for serum lactate dehydrogenase (LDH) activity, brain tissue superoxide dismutase (SOD) activity, and brain tissue malonaldehyde (MDA) content detection. It was found that serum LDH activity increased in rats of SAH group comparing with non-SAH group. SAH also resulted in decreased brain tissue SOD activity and increased brain tissue MDA content. In rats of SAH + CLB group, the increase of serum LDH activity was to a lager extent. Meanwhile, brain tissue SOD activity decreased and MDA content increased to a lager extent, as compared with SAH group. It was concluded that blockage of cerebral lymphatic drainage deteriorates cerebral oxidative injury after SAH, indicating cerebral lymphatic drainage may exert intrinsic protective effects against cerebral injury following SAH.