肠缺血再灌注损伤对血清及脂肪组织Leptin水平的影响

背景近年来的研究发现脂肪组织不仅仅是脂肪的储存库,还是一种能够分泌多种功能性细胞因子的多潜能内分泌器官.Leptin是一种由脂肪组织特异性分泌的蛋白质,主要功能是抑制摄食和增加能量消耗.目的研究肠缺血再灌注损伤对血清及脂肪组织Leptin水平的影响,探讨Leptin在急性炎症反应中的作用.设计完全随机设计,自身及组间对照.地点和材料本实验于解放军总医院生化研究室完成.3只雄性新西兰白兔及54只雄性SD大鼠作为实验动物.干预免疫新西兰白兔获得Leptin抗体,采用氯胺-T法碘标记Leptin抗原,由此建立一种简便的鼠Leptin放射免疫分析法.建立大鼠肠缺血再灌注损伤模型,实验大鼠随机分为6组假手术组(sham)、缺血60min-再灌注30min组(I60-R30),I60-R90,I60-R150,I60-R240及I60-R360组,每组9只.主要观察指标采用放射免疫分析法测量血清及脂肪组织Leptin浓度变化.结果与损伤前自身对照组的血清Leptin水平相比,肠缺血60min再灌注损伤30min(I60-B30)组显著降低(t=2.3891, P＜0.05),I60-R150组呈现增高的趋势,而I60-R360组显著增高(t=-2.343 7,P＜0.05);与损伤后sham组的血清Leptin水平(9.88±1.87)βg/L相比,I60-R240组呈现增高的趋势,而I60-R360组(19.43±2.84)μg/L显著增高(t=-2.8085,P＜0.05);与损伤后sham组的脂肪组织Leptin水平(11.12±1.27)ng相比,I60-R30(4.46±2.63)ng、I60-R90组(3.45±2.77)ng显著降低(t=2.2804,2.517 0,两者P均＜0.05),而I60-R360组(17.54±1.87)ng显著增高(t=-2.840 1,P＜0.05).结论Leptin对肠缺血-再灌注损伤等急性炎症刺激具有时间依赖效应,并在急性炎症反应的能量代谢障碍中发挥一定作用.

Effect of intestinal ischemia-reperfusion injury on the leptin levels in serum and adipose tissue

BACKGROUND: Recent studies suggest that adipose tissue is not only the reservation of fat, but also a multi-potential endocrine organ secreting many functional cytokines. Leptin is a protein specifically secreted by adipose tissue, and primarily reduces food-intake and promotes energy expenditure.OBJECTIVE: To explore the effect of intestinal ischemia-reperfusion injury on leptin levels in serum and adipose tissue, and find out the role of leptin playing in acute inflammatory responses.DESIGN: A completely random self-and mutual-control experiment.SETTING and MATERIALS: The experiment was collected and completed in Research Laboratory of Biochemistry, General Hospital of Chinese PLA.Three male New Zealand white rabbits and fifty-four male Sprague-Dawley rats were used for experimental use.INTERVENTIONS: New Zealand white rabbits were immunized to obtain anti-leptin, leptin antigen was iodinated by chloramines-T method, thus we established a concise radioimmunoassay for murine leptin. An intestinal ischemia-reperfusion injury model of rats was established, and rats were divided randomly into six groups: sham-operation group(sham), 60-minute ischemia and 30-minute reperfusion group(I60-R30), I60-R90, I60-R150,I60-R240 and I60-R360; each group contained nine rats.MAIN OUTCOME MEASURES: The changes of leptin concentrations in serum and adipose tissue before and after ischemia-reperfusion injury were checked by the radioimmunoassay.RESULTS: Compared with self-control(before injury), serum leptin level of I60-R30 decreased significantly(t=2.3891, P＜0.05), that of I60-R150 expressed a trend to increase and that of I60-R360 increased significantly ( t = - 2. 3437, P＜0.05 ). Compared with sham after injury [ (9.88±1.87)μg/L], serum leptin level of I60-R240 expressed a trend to increase, that of I60-R360[ (19.43±2.84) μg/L] increased significantly( t = - 2. 8085, P ＜0.05) . Compared with sham after injury [ ( 11.12±1.27 ) ng], adipose leptin levels of I60-R30[ (4.46±2.63) ng]and I60-R90[ (3, 45±2.77) ng] decreased significantly( t = 2. 2804 and 2. 5170, respectively, both P＜0.05), while that of I60-R360[(17.54±1.87)ng] increased significantly( t = -2. 8401, P＜0.05).CONCLUSION: Leptin has a time-dependent response to acute inflammatory stimuli and participates in the energy metabolic disorders of acute inflammation.