Kazez A, Demirbağ M, Ustündağ B, Ozercan I H, Sağlam M
First University, Medical Faculty, Department of Pediatric Surgery, Elaziğ, Turkey.
J Pediatr Surg. 2000 Oct;35(10):1444-8. doi: 10.1053/jpsu.2000.16410.
BACKGROUND/PURPOSE: The aim of this study was to determine the effect of melatonin, a hormone that is known as an antioxidant, on the prevention of tissue damage during mesenteric ischemia/reperfusion (I/R).
A total of 40 young Wistar-albino rats were divided equally into 4 groups with varied treatment. Group 1 was control (sham), group 2 was I/R, group 3 was I/R plus melatonin (10 mg/kg) and group 4 was I/R plus melatonin (20 mg/kg). I/R was realized as follows: after laparatomy, a microvascular atraumatic clip was placed across the superior mesenteric artery (SMA) under general anaesthesia, and it was removed after ischemia for 30 minutes. The first dose of melatonin was applied intraperitoneally at the start of reperfusion. The second and third doses were applied intramuscularly on the first and second day. Only SMA dissection under general anaesthesia was carried out in the control group rats. On the third day of the study all the rats were killed, and their bowels were removed. Malondialdehyde (MDA) levels were assayed as an index of lipid peroxidation reflecting free radical reaction in the intestine. Histopathologic analysis was made using light microscopy in a blind fashion.
The levels of tissue MDA were found to be significantly lower in groups 3 and 4 compared with group 2 (P < .05). The MDA levels of group 4 did not differ significantly from that of the control group (P > .05). The histopathologic results were consistent with the MDA levels.
These results suggest that melatonin has a strong antioxidant effect in preventing intestinal I/R damage, and that this effect is exerted in a dose-dependent manner.
背景/目的：本研究旨在确定褪黑素（一种已知的抗氧化激素）对预防肠系膜缺血/再灌注（I/R）期间组织损伤的作用。
总共40只年轻的Wistar白化大鼠被平均分为4组，接受不同的治疗。第1组为对照组（假手术组），第2组为I/R组，第3组为I/R加褪黑素（10毫克/千克）组，第4组为I/R加褪黑素（20毫克/千克）组。I/R的实现方式如下：剖腹术后，在全身麻醉下将微血管无创夹置于肠系膜上动脉（SMA）上，缺血30分钟后移除夹子。在再灌注开始时腹腔内注射第一剂褪黑素。第二剂和第三剂在第一天和第二天肌肉注射。对照组大鼠仅在全身麻醉下进行SMA解剖。在研究的第三天，所有大鼠被处死，并取出它们的肠道。测定丙二醛（MDA）水平，作为反映肠道自由基反应的脂质过氧化指标。使用光学显微镜以盲法进行组织病理学分析。
发现第3组和第4组的组织MDA水平与第2组相比显著降低（P <.05）。第4组的MDA水平与对照组无显著差异（P >.05）。组织病理学结果与MDA水平一致。
这些结果表明，褪黑素在预防肠道I/R损伤方面具有强大的抗氧化作用，且这种作用呈剂量依赖性。
