The Roles Of Pannexin 1 In Global Cerebral Ischemia/reperfusion

Pannexin 1(Panx 1) is one of the newly discovered channel proteins,named Pannexins.Panx 1 has been reported to form transmembrane gap junction hemichannel which is permeable to ions and small molecules.Panx 1 hemichannel is opened during oxygen and glucose deprivation on hippocampal pyramidal neurons but the effects of Panx 1 protein during cerebral ischemia/reperfusion(IR) injuries are still unclear.This experiment was to detect the expression pattern of Panx 1 in rat's central nervous system and to investigate the effects of Panx 1 during global IR in rats.We comparedd the expression level of Panx 1 in newborn and adult rats and detected the changes of protein contents in global brain ischemia and reperfusion in adult rats by western blotting,and we also investigated the effects of Panx 1 channels on IR-induced neural death by blocking the channels by probenecid(PB).We found highly expression levels of Panx 1 in newborn rats but much lower levels in adult brains.We also found that the glycosylation level of Panx 1 was increased although the protein contents showed no change during global brain ischemia and reperfusion.Moreover,PB at lower concentration(0.1 mg/kg,1mg/kg) reduced hippocampal neural death after 10-min global cerebral ischemia while PB at higher concentration(10 mg/kg,100 mg/kg) aggravated the injuries.We concluded that Panx 1 protein plays an important role in rat's development and in IR-induced neural death.Further investigation of functions formed by Panx 1 channels may uncover a new pathway underlying IR injuries and provide a new target for clinical therapy of brain ischemia.