Role of c-Jun N-terminal kinase signaling pathway in the protective effect of isoflurane preconditioning and sevoflurane preconditioning against oxygen-glucose deprivation injury in rat hippocampal slices

Abstract

Objective To evaluate the role of c-Jun N-terminal kinase (JNK) signaling pathway in the protective effect of isoflurane preconditioning and sevoflurane preconditioning against oxygen-glucose deprivation (OGD) injury in rat hippocampal slices. Methods Male adult SD rats weighing 270-290 g were anesthetized with ether and decapitated. The hippocampi were removed and sagittally sliced (400 μm thick) and placed in artificial cerebral spinal fluid aerated with 95% O2-5% CO2 . Ninety-six hippocampal slices were randomly divided into 8 groups (n = 12 each): control group (group C), OGD group, isoflurane preconditioning group (group Iso),sevoflurane preconditioning group (group Sevo) , SP600125 + isoflurane preconditioning group (group SP + Iso),SP600125 +sevoflurane preconditioning group (group SP + Sevo), DMSO + isoflurane preconditioning group (group DMSO + Iso) and DMSO + sevoflurane preconditioning group (group DMSO + Sevo). Electrophysiological technique was used to record the amplitude of population spike ( PS) in the stratum pyramidale of CA1 region and the degree of recovery of PS was calculated. The cell viability was determined by propidium iodide staining. Results Compared with group C, the degree of recovery of PS and cell viability were significantly decreased in the other groups ( P ＜ 0.01) . Compared with group OGD, the degree of recovery of PS and cell viability were significantly increased in groups Iso, Sevo, SP+Iso, SP+Sevo, DMSO+ Iso and DMSO + Sevo (P＜ 0.01). Compared with group Iso, the degree of recovery of PS and cell viability were significantly increased in group SP+Iso ( P ＜ 0.01) , while no significant change was found in group DMSO + Iso ( P ＞ 0.05) . Compared with group Sevo, the degree of recovery of PS and cell viability were significantly increased in group SP + Sevo ( P ＜ 0.01) , while no significant change was found in group DMSO + Sevo ( P ＞ 0.05). Conclusion Isoflurane preconditioning and sevoflurane preconditioning can attenuate the OGD injury to rat hippocampal slices through inhibiting JNK signaling pathway. Key words: JNK mitogen-activated protein kinases; Isoflurane; Anesthetics, inhalation; Ischemic preconditioning; Brain ischemia; Hippocampus