Cystain C and neuropeptid Y levels in brain tissues after experimental subarachnoid hemorrhage

The aim of this study was to investigate the changes in the levels of cystatin C, which protects neurodegeneration in the central nervous system with the inhibition of cysteine protease and by inducing autophagy in the pathogenesis of cerebral vasospasm and levels of vasoconstrictive neuropeptid Y (NPY) in the brain tissue homogenates of rat model of subarachnoid hemorrhage (SAH). Three experimental groups were used: Day 2 and Day 7 groups after SAH, and also a control group. There were seven Wistar albino rats in each group. SAH was accomplished by transclival basilar artery puncture. Rat cystatin C, rat NPY were determined with ELISA in brain tissue homogenates. Day 2 group showed significantly enhanced cystatin C values in comparision with the control group (P=0.048). NPY levels between the Day 2 and Day 7 groups and the control groups were not significantly different (P=0.315). In histopathological examination, there was less neuronal loss in the Day 2 group than in the Day 7 group. Regarding our results, it would be more valuable to measure NPY levels in specific brain areas. The increased cystatin C levels on the second day after SAH is probably a pathophysiologic mechanism to organize protease activity.