Combined preconditioning with hypoxia and GYKI-52466 protects rats from cerebral ischemic injury by HIF-1α/eNOS pathway.

Cerebral ischemic injury has been the leading cause of death and long term disability in the world because of the lack of successful therapies to it, leading to neurological and behavioral deficits. The present study aims to investigate the effects of combined preconditioning (PC) with hypoxia and GYKI-52466 (GYKI) on cerebral ischemic injury and to explore the mechanism. The results showed that combined preconditioning with hypoxia and GYKI-52466 increased the survival rate of cerebral ischemia rats, alleviated the neurological deficit, increased the object recognition and social recognition memory of rats and suppressed the inflammatory reaction induced by cerebral ischemia. Further experiments found that preconditioning with hypoxia and GYKI-52466 significantly increased the HIF-1α and eNOS expression as well as eNOS activity, while inhibitors of HIF-1α and eNOS abolished the protective effects of hypoxia+GYKI PC on neurological deficit. Taken together, these results indicate that combined preconditioning with hypoxia and GYKI-52466 is effective to prevent cerebral ischemia injury, while HIF-1α and eNOS may be involved in the mechanism.