武汉云克隆科技股份有限公司

Abstract:

Oxidative stress induced by spinal cord injury (SCI) has deleterious effects on the function of several organ systems including the urinary bladder. In this study, we investigated the possible protective actions of melatonin on SCI-induced oxidative damage and urinary bladder dysfunction. Wistar albino rats (n = 24) were divided randomly as control, vehicle- or melatonin (10 mg/kg, ip)-treated SCI groups. To induce SCI, a standard weight-drop method that induced a moderately severe injury at T10 was used. Injured animals were given either vehicle or melatonin 15 min postinjury. One week postinjury, each rat was neurologically examined and then decapitated; blood samples were taken to evaluate neuron-specific enolase (NSE) and soluble protein 100β (S-100β). Spinal cord (SC) and urinary bladder samples were taken for functional studies and histological examination or stored for the measurement of malondialdehyde (MDA), glutathione (GSH) and nerve growth factor (NGF) levels and caspase-3 activity. Isometric contractions in bladder strips were induced by carbachol. In the SCI rats, decreased contractile responses of the bladder strips were found to be restored by melatonin treatment. Serum S-100β levels and NSE activities and tissue MDA levels and caspase-3 activities, all of which were elevated in the vehicle-treated SCI animals as compared to the control values, were reversed by melatonin treatment. On the other hand, reduced GSH and NGF levels due to SCI were restored by melatonin treatment. Furthermore, melatonin treatment improved histological findings. These findings suggest that melatonin reduces SCI-induced tissue injury and improves bladder functions through its effects on oxidative stress and NGF.

摘要：

脊髓损伤(SCI)引起的氧化应激对包括膀胱在内的多种器官系统的功能有不良影响。本课题中，我们研究了褪黑素对脊髓损伤和膀胱功能障碍的保护作用。将24只实验大鼠随机分组为对照组、溶剂组、褪黑素(10mg/kg，腹腔注射)组。大鼠脊髓损伤模型建立采用标准的重滴法，在T10处造成中度严重损伤。建模完成后15分钟注射溶剂或褪黑素。建模一周，对每只大鼠进行神经学检查后开颅，取血样检测神经元特异性烯醇化酶(NSE)和可溶性蛋白100β(S-100β)。取脊髓(SC)和膀胱标本进行功能学研究和组织学检测，或保存样本以测定丙二醛(MDA)、谷胱甘肽(GSH)、神经生长因子(NGF)和caspase-3活性。碳酰胆碱可诱导膀胱条等长收缩，对脊髓损伤大鼠进行褪黑素处理后膀胱条收缩反应减弱。溶剂组中血清S-100β水平、NSE活性、组织MDA含量和caspase-3活性均较对照组升高，而褪黑素处理组则结果相反。另一方面，经褪黑激素治疗SCI的大鼠GSH和NGF水平降低。此外，褪黑素治疗改善了组织学检查结果。研究揭示了褪黑素通过对氧化应激和NGF的影响，减轻SCI引起的组织损伤从而改善膀胱功能。

使用试剂原文信息：Serum levels of neuron-specific enolase (NSE) and soluble protein-100b (S-100b) levels were assayed using ELISA kits for rats (USCN Life Science & Technology Company,Missouri, TX, USA)