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AIM: To evaluate preventative effects of ischemic preconditioning(IP) in a rat model of intestinal injury induced by ischemia-reperfusion(IR).METHODS: Male Sprague-Dawley rats(250-300 g) were fasted for 24 h with free access to water prior to the operation.Eighteen rats were randomly divided into three experimental groups: S group(n = 6),rats were subjected to isolation of the superior mesenteric artery(SMA) for 40 min,then the abdomen was closed; IRgroup(n = 6),rats were subjected to clamping the SMA 40 min,and the abdomen was closed followed by a 4-h reperfusion; IP group(n = 6) rats underwent three cycles of 5 min ischemia and 5 min reperfusion,then clamping of the SMA for 40 min,then the abdomen was closed and a 4-h reperfusion followed.All animals were euthanized by barbiturate overdose(150 mg/kg pentobarbital sodium,i.v.) for tissue collection,and the SMA was isolated via median abdominal incision.Intestinal histologic injury was observed.Malondialdehyde(MDA),myeloperoxidase(MPO) and tumor necrosis factor(TNF)-a concentrations in intestinal tissue were measured.Intercellular adhesion molecule(ICAM)-1 and vascular cell adhesion molecule(VCAM)-1 expression,as well as nuclear factor(NF)-κB activity and expression in intestinal tissue were also determined.RESULTS: Compared with the IR group,IP reduced IR-induced histologic injury of the intestine in rats(2.00 ± 0.71 vs 3.60 ± 0.84,P < 0.05).IP significantly inhibited the increase in MDA content(5.6 ± 0.15 μmol/L vs 6.84 ± 0.18 μmol/L,P < 0.01),MPO activity(0.13 ± 0.01 U/L vs 0.24 ± 0.01 U/L,P < 0.01),and TNF-a levels(7.79 ± 2.35 pg/m L vs 10.87 ± 2.48 pg/m L,P < 0.05) in the intestinal tissue of rats.IP also markedly ameliorated the increase in ICAM-1(204.67 ± 53.27 vs 353.33 ± 45.19,P < 0.05) and VCAM-1(256.67 ± 58.59 vs 377.33 ± 41.42,P < 0.05) protein expression in the intestinal tissues.Additionally,IP remarkably decreased NF-κB activity(0.48 ± 0.16 vs 0.76 ± 0.22,P < 0.05) and protein expression(320.23 ± 38.16 vs 520.76 ± 40.53,P < 0.01) in rat intestinal tissue.CONCLUSION: IP may protect against IR-induced intestinal injury by attenuation of the neutrophilendothelial adhesion cascade via reducing ICAM-1 and VCAM-1 expression and TNF-a-induced NF-κB signaling pathway activity.
AIM: To evaluate preventative effects of ischemic preconditioning (IP) in a rat model of intestinal injury induced by ischemia-reperfusion (IR) .METHODS: Male Sprague-Dawley rats (250-300 g) were fasted for 24 h with free access to The animals were subjected to isolation of the superior mesenteric artery (SMA) for 40 min, then the abdomen was closed; IRgroup (n = 6), rats were subjected to clamping the SMA 40 min, and the abdomen was closed followed by a 4-h reperfusion; IP group (n = 6) rats underwent three cycles of 5 min ischemia and 5 min reperfusion, then clamping of the SMA for 40 min, then the abdomen was closed and a 4-h reperfusion followed. All animals were euthanized by barbiturate overdose (150 mg / kg pentobarbital sodium, iv) for tissue collection, and the SMA was isolated via median abdominal incision. Intestinal histologic injury was observed. Malondialdehyde (MDA), myeloperoxidase (MPO) and tumor necrosis factor (TNF) -a concentrations in intestinal tissue were measured.Intercellular adhesion molecule (ICAM) -1 and vascular cell adhesion molecule (VCAM) -1 expression, as well as nuclear factor (NF) -κB activity and expression in Intestinal tissue were also determined. RESULTS: Compared with the IR group, IP reduced IR-induced histologic injury of the intestine in rats (2.00 ± 0.71 vs. 3.60 ± 0.84, P <0.05) (0.13 ± 0.01 U / L vs 0.24 ± 0.01 U / L, P <0.01), and TNF-a levels (7.79 ± 2.35 pg / m L vs. 10.87 ± 2.48 pg / m L, P <0.05) in the intestinal tissue of rats. IP also markedly ameliorated the increase in ICAM-1 (204.67 ± 53.27 vs 353.33 ± 45.19, P <0.05) (256.67 ± 58.59 vs 377.33 ± 41.42, P <0.05), protein expression in the intestinal tissues. Additionally, IP remarkably decreased NF-κB activity (0.48 ± 0.16 vs 0.76 ± 0.22, P <0.05) sion (320.23 ± 38.16 vs. 520.76 ± 40.53, P <0.01) in rat intestinal tissue. CONCLUSION: IP may protect against IR-induced intestinal injury by attenuation of the neutrophil endothelial adhesion cascade via reducing ICAM-1 and VCAM-1 expression and TNF-a-induced NF -κB signaling pathway activity.