ObjectiveTo observe the changes of early cerebral microcirculation after subarachnoid hemorrhage (SAH) and the effect of nitric oxide (NO) expression on early brain injury (EBI) and cerebral microcirculation after SAH.

MethodsEighty New Zealand white rabbits were divided into the operation group and sham operation group, then the two groups were further divided into 4 subgroups including 1 h, 6 h, 24 h and 72 h after operation, with 10 rabbits in each subgroup.SAH model was established by injecting autologous blood into cisterna magna in operation group, and injecting 0.9% sodium chloride solution with the same method in sham operation group.The CT perfusion imaging of whole brain was performed to compare the cerebral blood flow(CBF), cerebral blood volume(CBV), mean transit time(MTT), time to peak (TTP) and NO content in each group, and the correlation between NO and CBV, CBF, MTT, TTP was analyzed.

ResultsCBV and CBF in operation group were significantly lower than those in sham operation group at 1 h, 6 h, 24 h and 72 h after operation (P<0.01), and MTT was higher than that in sham operation group(P<0.05 to P<0.01);TTP in operation group was higher than that in sham operation group at 24 h and 72 h after operation(P<0.01 and P<0.05).There was no significant change in the NO content at 1 h, 6 h, 24 h and 72 h after operation in sham operation group(P>0.05), but the NO content increased at 24 h and 72 h after operation in operation group(P<0.01);at 1 h, 6 h, 24 h and 72 h after operation, the NO content in operation group was significantly lower than that in the corresponding sham operation group(P<0.01).Linear correlation analysis showed that NO was negatively correlated with MTT(r=-0.854, P<0.05) and positively correlated with CBF(r=0.786, P<0.05).

ConclusionsCT perfusion can detect the focal cerebral ischemia after SAH in early stage, which reflects the pathological progress of EBI after SAH.NO affects the microcirculation changes and the progress of EBI after SAH to some extent.