| Obiective: To observe the effect of ischemic postconditioning on expression of HSP70, HSP27 and HO-1 in rats after kidney ischemia reperfusion injury. To investigate the mechanism of ischemic postconditioning relieving kidney ischemia reperfusion injury.Methods: One hundred forty healthy male SD rats weighing 250-280 g were randomized into 4 groups: sham operation group(group S); ischemic reperfusion group (group I/R); ischemic postconditioning group(group IPo) and Quercetin+ischemic postconditioning group (group Q+IPo). Each group had 0h(T0), 1h(T1), 3h(T2), 6h(T3), 12h(T4), 24h(T5), and 48h(T6) subgroups(5 rats in each group) . The rats were anesthetized with intraperitoneal chloral hydrate 300 mg·kg-1. Bilateral kidneys were exposed through midline incision and bilateral renal pedicels were occluded for 45 min with atraumatic mini-clamp then unclamped and time recorded. In group S, bilateral kidneys were exposed for 45 min through a midline incision but their pedicels were not clamped. In group I/R, bilateral renal pedicels were clamped for 45 min soon after reperfusion; In group IPo and Q+IPo, 45 min ischemia followed by three 10 s episodes of ischmeia at 10 s interval for reperfusion; In group Q+IPo, quercetin(inhibitor of HSP70 expression)100 mg.kg-1 were given IP at 1h before ischmeia. The kidneys were removed to detect the expression of HSP70mRNA, HSP27mRNA, HO-1mRNA and HSP70, HSP27, HO-1 protein content at each time stage by real-time RT-PCR and immunohistochemistry staining technique. At 6h after reperfusion blood samples were obtained to determine serum creatinine(Cr) and urea nitrogen(BUN) concentrations; and to detect nephridial tissue MDA level and SOD activity; the apoptosis was assessed using TUNEL and apoptotic index(AI) was calculated in the nephridial tissue. Caspase-3mRNA were detected by real-time RT-PCR; The expression of NF-κB in nephridial tissue was detected by immunohistochemistry staining technique; The TNF-αlevel in plasm was detected ; Histopathology was observed with light microscope .Results: The expression of HSP70mRNA and HSP70 protein: In group S HSP70 mRNA and HSP70 protein have no evident expression nearly, in the other groups the expression of HSP70 mRNA and HSP70 protein increased at T0 and met peakpoint at T3, then began to decrease. Compared with group S, the expression of HSP70mRNA and HSP70 protein increased at T0~T6 (P< 0.05) in other groups. Compared with group I/R, the expression of HSP70mRNA and HSP70 protein in group IPo were significantly higher at T1~T5 (P< 0.05), the peak value at T3 was increased(P< 0.05). Compared with group IPo, the expression of HSP70mRNA and HSP70 protein in group Q+IPo were significantly lower at T1~T5 (P< 0.05), the peak value at T3 was decreased (P< 0.05); btween the group I/R and Q+IPo, there have no significantly defference.The expression of HO-1mRNA and HO-1 protein: In group S HO-1 mRNA and HO-1 protein have no evident expression nearly, in the other groups the expression of HO-1 mRNA and HO-1 protein increased at T0 and met peakpoint at T3, then began to decrease. Compared with group S, the expression of HO-1mRNA and HO-1 protein increased at T0~T6 (P< 0.05) in other groups. Compared with group I/R, the expression of HO-1mRNA and HO-1 protein in group IPo were significantly higher at T1~T5 (P< 0.05), the peak value at T3 was increased (P< 0.05). Compared with group IPo, the expression of HO-1mRNA and HO-1 protein in group Q+IPo were significantly lower at T1~T5 (P< 0.05), the peak value at T3 was decreased (P< 0.05); btween the group I/R and Q+IPo, there have no significantly defference.The expression of HSP27mRNA and HSP27 protein: In group S HSP27 mRNA and HSP27 protein have no evident expression nearly, in the other groups the expression of HSP27 mRNA and HSP27 protein increased at T0 and met peakpoint at T3, then began to decrease. Compared with group S, the expression of HSP27mRNA and HSP27 protein increased at T0~T6 (P< 0.05) in other groups. Compared with group I/R, the expression of HSP27mRNA and HSP27 protein in group IPo were significantly higher at T2~T5 (P< 0.05), the peak value at T3 was increased (P< 0.05). Compared with group IPo, the expression of HSP27mRNA and HSP27 protein in group Q+IPo were significantly lower at T2~T5 (P< 0.05), the peak value at T3 was decreased (P< 0.05); btween the group I/R and Q+IPo, there have no significantly defference.Serum Cr and urea BUN concentrations, the expression of caspase-3mRNA and AI: compared with the group S, at 6h after the reperfusion the Cr and BUN concentrations, caspase-3mRNA and the AI were all significantly increased (P< 0.05) in other groups. compared with the group I/R, Serum Cr and urea BUN concentrations, caspase-3mRNA and the AI were decreased and histopathoiogyof kidney was attenuated in group IPo (P< 0.05); compared with the group IPo, the Cr and BUN concentrations, caspase-3mRNA and the AI were all significantly increased in group Q+IPo (P< 0.05). btween the group I/R and Q+IPo, Serum Cr and urea BUN concentrations caspase-3mRNA and AI were not significantly defferent.MDA level, SOD activity and NF-κB, TNF-αlevel: compared with the group S, the MDA contents, expression of NF-κB and plasm TNF-αlevel were all significantly increased while the SOD activity were significantly decreased (P< 0.05) in group I/R,IPo and Q+IPo at 6h after the reperfusion; compared with the group I/R, the MDA contents, expression of NF-κB and plasm TNF-αlevel were all significantly decreased while the SOD activity were significantly increased (P< 0.05) in group IPo at 6h after the reperfusion; compared with the group IPo, the MDA contents, expression of NF-κB and plasm TNF-αlevel were all significantly increased while the SOD activity were significantly decreased (P< 0.05) in group Q+IPo at 6h after the reperfusion; between group I/R and Q+IPo, the MDA level, SOD activity and NF-κB, TNF-αlevel were not significantly defferent.Conclusion: Ischemic postconditioning can increase the expression of HSP70mRNA, HSP27mRNA, HO-1mRNA and HSP70, HSP27, HO-1 protein. At the same time, it can increase the peak value in rats after kidney ischemia reperfusion injury, which could attenuate the injury from kidney ischemia reperfusion. |
