RESUMO
Objective To investigate the effect of hyperbaric oxygen preconditioning on syngeneic kidney transplantation in rats and to explore the potential mechanism. Methods Forty male SD rats were randomly divid-ed into control group(Sham group),kidney transplantation group(KTx group)and hyperbaric oxygen precondi-tioning group(HBO+KTx group). Kidney transplantation was performed 24 h after hyperbaric preconditioning. Rats were sacrificed 24 h after the transplantation.Serum creatinine(Scr)and blood urea nitrogen(BUN)were de-tected.The level of superoxide dismutase(SOD),malondialdehyde(MDA)and heme oxygenase-1(HO-1)in the graft was examined. Kidney pathological examination was performed after renal tissue fixed. Results Compared with the KTx group,HBO + KTx group showed lower Scr and BUN level. The MDA level was decreased and the SOD activity was increased significantly after hyperbaric oxygen preconditioning in HBO+KTx group.Renal tubu-lar necrosis was significantly reduced in HBO+KTx group.HO-1 level in HBO+KTx group was significantly high-er than that of KTx group. Conclusion Hyperbaric oxygen preconditioning can reduce lipid peroxidation,en-hance antioxidant enzyme activity and improve the level of HO-1 in graft tissue,thus attenuating kidney injury.
RESUMO
Objective To explore the effects of hyperbaric oxygen preconditioning on ischemia-reperfusion inflammatory reaction of rats after skin flap transplantation.Methods Fifty-six Sprague-Dawley rats were randomly divided into 3 groups:a sham ischemia-reperfusion (SH) group,an ischemia-reperfusion (IR) group and a hyperbaric oxygen reconditioning (HBO) group.Both IR group and HBO group were further divided into 3 subgroups,respectively,according to the time points of serum sampling for test post establishment of the IR model of the abdominal pedicle skin flap transplantation.The IR model of the abdominal pedicle skin flap transplantation was established in all the animals except those in the SH group,with those in the HBO group were preconditioned with HBO twice daily for 3 days before the operation.The blood was sampled at 1,3 and 5 day post-operation to test the level of IL-23 using enzyme-linked immunosorbeut assay (ELISA).The survival skin flaps were sampled from all the animals at 3 and 5 days after the operation for histological observation and evaluation.Results The average IL-23 level of HBO 3 d subgroup (17.80 ± 14.78) was significantly lower than that of the IR 3 d subgroup (38.91 ± 12.26).The average histological scores of the IR 3 d and 5 d subgroups,as well as HBO 3 d and 5 d subgroups were (2.66 ±0.44)and (3.2 ±0.53),(1.85 ±0.31) and (2.29 ±0.32),significantly higher than SH group (0.38 ±0.10).Moreover,the average histological score of the HBO 3 d and 5 d subgroups was significantly lower than IR 3 d and 5 d subgroups respectively.Conclusion Hyperbaric oxygen preconditioning can relieve the ischemia-reperfusion inflammatory reaction through reducing the serum level of IL-23 in rats after skin flap transplantation.
RESUMO
Objective To investigate the effect of hyperbaric oxygen preconditioning (HBO) on activation of extracellular signal-regulated kinase (ERK) and death-associated protein kinase 1 (DAPK1)in ischemia-like treated neurons.Methods (1) Cultured mouse primary neurons were allocated into control,ischemia-like condition treated and HBO preconditioning groups.Neurons in ischemia-like condition treated group were treated with 95％ NO2+5％ CO2 for 30 min,and cells in the HBO preconditioning group were pretreated with 98％ O2+2％ CO2 for 2 h,followed by ischemia-like condition treatment.At the end ofthe treatment,the growth of neurons was measured by MTT assay and expression of phosphorylated extracellular signal-regulated kinase (p-ERK) was detected by Western blotting.Neurons were transfected with ERK over-expression vector and pretreated with HBO and ischemia-like condition,and then,the expressions of activated caspase-3 (cleavage caspase-3) and DAPK1 in neurons were analyzed by Western blotting.The interactions of ERK with DAPK1 were also detected by irnmunoprecipitation.(2) Forty-five BALB/c mice were randomized into control,ischemia treated and HBO preconditioning groups.After finishing the treatments,the interactions of ERK with DAPK1 in hippocampal neurons were detected by immunoprecipitation.Results As compared with control group,cells in ischemia-like condition group showed a reduction of cell survivals,while cells in HBO preconditioning group exhibited an inhibition effect on ischemia-like condition-induced cell survival reduction.The expressions of p-ERK were increased by ischemia-like condition,while decreased by HBO preconditioning,with significant difference (P＜0.05).Moreover,over-expression of ERK promoted level of cleavage caspase-3 in neurons; however,DAPK1 expressions were not affected by ischemia-like condition or HBO preconditioning.The interactions of ERK with DAPK1 were attenuated by HBO preconditioning as compared with those by ischemia-like condition treatment.Conclusion HBO preconditioning inhibits ERK activation and disturbs the interaction between ERK and DAPK1,which blocks cell apoptosis and thus induces ischemic tolerance.