Halıcı Mehmet, Öner Mithat, Güney Ahmet, Canöz Özlem, Narin Figen, Halıcı Canan
Department of Orthopedics and Traumatology, Erciyes University, Kayseri, Turkey.
Eklem Hastalik Cerrahisi. 2010 Dec;21(3):172-7.
In this study, we investigated the effect of melatonin on fracture healing in the rat tibia model by using biochemical and histopathologic methods.
In this study 80 male Sprague-Dawley rats were randomized into two groups, a control group (Group 1) and melatonin group (Group 2) with eight rats per group according to the day of sacrifice (Days 1, 3, 7, 14 and 28). The fractures were produced by the manual breakage using plate-bending devices, placed at the distal 3(rd) of the right tibia. Group 2 received 30 mg/kg/day melatonin and group 1 1% alcohol in saline 5 ml/kg/day intraperitoneally during the experiment. Plasma Malondialdehyde (MDA) levels, activity of superoxide dismutase (SOD) and myeloperoxidase (MPO) were measured biochemically. The fracture healing was evaluated using a five-point scale defined by Allen et al.
Malondialdehyde levels in group 2 decreased at days 3, 7, 14, and 28 compared to control values (p<0.05). Superoxide dismutase activity in group 2 decreased at days 3, 7 and 14, and returned to the 1(st) day value after 28 days. Myeloperoxidase values in group 2 decreased at days 1, 3, and 7 (p<0.001). Histopathological specimens of healed tibias showed two animals with complete cartilaginous union, five with incomplete bony union and one with complete bony union in the group 2. In contrast, in the group 1, six rats showed complete cartilaginous union and two showed incomplete cartilaginous union (p<0.05).
The administration of melatonin maybe beneficial in suppressing the effects of free oxygen radicals and regulating antioxidant enzyme activity in the fracture healing process.
在本研究中，我们通过生化和组织病理学方法研究了褪黑素对大鼠胫骨模型骨折愈合的影响。
本研究将80只雄性Sprague-Dawley大鼠随机分为两组，即对照组（第1组）和褪黑素组（第2组），每组8只大鼠，根据处死天数（第1、3、7、14和28天）进行分组。使用钢板弯曲装置手动造成骨折，骨折部位位于右胫骨远端三分之一处。在实验期间，第2组大鼠腹腔注射30 mg/kg/天的褪黑素，第1组大鼠腹腔注射5 ml/kg/天含1%酒精的生理盐水。通过生化方法测量血浆丙二醛（MDA）水平、超氧化物歧化酶（SOD）和髓过氧化物酶（MPO）的活性。使用Allen等人定义的五点量表评估骨折愈合情况。
与对照组相比，第2组在第3、7、14和28天的丙二醛水平降低（p<0.05）。第2组的超氧化物歧化酶活性在第3、7和14天降低，并在28天后恢复到第1天的值。第2组的髓过氧化物酶值在第1、3和7天降低（p<0.001）。愈合胫骨的组织病理学标本显示，第2组中有2只动物实现了完全软骨联合，5只实现了不完全骨联合，1只实现了完全骨联合。相比之下，在第1组中，6只大鼠显示完全软骨联合，2只显示不完全软骨联合（p<0.05）。
褪黑素的给药可能有助于在骨折愈合过程中抑制自由基的作用并调节抗氧化酶活性。
