MATERIAL and METHODS: Thirty-six male New Zealand White rabbits were randomly divided into three groups: 1) Control group (n=12): given conventional breeding and normal sodium (0.9%) was injected twice into the cisterna magna. 2) SAH group (n=12): given conventional breeding and a SAH model was established. 3) Simvastatin + SAH group (n=12): given conventional breeding and simvastatin for one week, and then a SAH model was established. The first cerebral angiography was conducted before the first injection of sodium or autologous blood into the cisterna magna. The second angiography was done three days after the second injection. The ultrastructural pathology of the basilar artery was compared in three groups. The expression of platelet-derived growth factor-β (PDGF-β), proliferating cell nuclear antigen (PCNA) and α-smooth muscle actin (α-SMA) in VSMCs was analysed by RT-PCR.

RESULTS: Angiography examinations showed that the basilar artery was obviously contracted in the SAH group and dCVS was confirmed existence after blood injection into the cisterna magna twice. The thickness of VSMCs in the SAH group increased and the expression of PDGF-β, PCNA, and α-SMA in SAH group were all increased compared to the control group (p<0.05), and decreased while prophylactic giving simvastatin (p<0.05).

CONCLUSION: Simvastatin may relieve dCVS after SAH by inhibiting the proliferation of VSMCs. Keywords : Subarachnoid hemorrhage, Delayed cerebral vasospasm, Vascular smooth muscle cell, Proliferation