Effect of thrombin injection on cerebral vascular in rats with subarachnoid hemorrhage

Objective To evaluate the effect of thrombin (TM) injection via the cerebellomedullary cistern on cerebral vessels in rats with subarachnoid hemorrhage (SAH). Methods Eighteen rats were randomly divided into three groups. In the A1 group, physiological saline was injected via the cerebellomedullary cistern; in the A2 group, 3 U of TM was injected into the subarachnoid space; and in the A3 group, SAH models were established and 3 U of TM was injected with the first injection of whole blood. Three days later, basilar artery specimens were collected for pathological examination. Results The basilar arterial lumen cross-sectional area was significantly smaller in the A2 versus the A1 group, and proteinase-activated receptor (PAR)-1 and tumor necrosis factor (TNF)-α average optical densities were significantly higher (all P < 0.05). Basilar arterial lumen cross-sectional areas were significantly smaller in the A3 than the A2 group and average TNF-α optical densities were significantly lower (both P < 0.05), while those of PAR-1 did not differ significantly. Conclusions There was no significant difference in the extent of cerebral vasospasm between SAH and non-SAH model groups following TM injection into the subarachnoid space, so TM was considered to be an independent factor affecting cerebral vasospasm