糖尿病神经病变(DN)是糖尿病最常见的并发症。DN的药物治疗通常疗效有限,因此,开发新的药物来缓解DN至关重要。本研究的目的是评估咯利普兰的效果,选择性磷酸二酯酶-4抑制剂(PDE-4I),和己酮可可碱,一般的PDE抑制剂,使用DN的大鼠模型。在这项研究中,通过腹腔注射STZ(55mg/kg)建立糖尿病大鼠模型。大鼠接受咯利普兰(1mg/kg)治疗,己酮可可碱(100mg/kg),以及咯利普兰(0.5mg/kg)和己酮可可碱(50mg/kg)的组合,口服5周。治疗后,通过热板试验评估感觉功能。然后将大鼠麻醉并分离背根神经节(DRG)神经元。环磷酸腺苷(cAMP),三磷酸腺苷(ATP,二磷酸腺苷和线粒体膜电位(MMP)水平,细胞色素c释放,Bax,通过生化和ELISA方法评估DRG神经元中Bcl-2,caspase-3蛋白的表达,和蛋白质印迹分析。使用苏木精和伊红(H&E)染色方法对DRG神经元进行组织学检查。罗利普兰和/或己酮可可碱通过调节伤害性阈值可显着减轻感觉功能障碍。罗利普兰和/或己酮可可碱治疗显著增加cAMP水平,防止线粒体功能障碍,DRG神经元的凋亡和变性,这似乎是通过诱导ATP和MMP介导的,改善细胞色素C释放,以及调节Bax的表达,Bcl-2和caspase-3蛋白,改善DRG神经元的形态异常。我们发现,在上述因素上,咯利普兰和己酮可可碱组合的效果最大。这些发现鼓励使用咯利普兰和己酮可可碱组合作为DN治疗的进一步临床研究的新实验证据。
Diabetic neuropathy (DN) is the most prevalent complication of diabetes. Pharmacological treatments for DN are often limited in efficacy, so the development of new agents to alleviate DN is essential. The aim of this study was to evaluate the effects of rolipram, a selective phosphodiesterase-4 inhibitor (PDE-4I), and pentoxifylline, a general PDE inhibitor, using a rat model of DN. In this study, a diabetic rat model was established by i.p. injection of STZ (55 mg/kg). Rats were treated with rolipram (1 mg/kg), pentoxifylline (100 mg/kg), and combination of rolipram (0.5 mg/kg) and pentoxifylline (50 mg/kg), orally for 5 weeks. After treatments, sensory function was assessed by hot plate test. Then rats were anesthetized and dorsal root ganglion (DRG) neurons isolated. Cyclic adenosine monophosphate (cAMP), adenosine triphosphate (ATP, adenosine diphosphate and mitochondrial membrane potential (MMP) levels, Cytochrome c release, Bax, Bcl-2, caspase-3 proteins expression in DRG neurons were assessed by biochemical and ELISA methods, and western blot analysis. DRG neurons were histologically examined using hematoxylin and eosin (H&E) staining method. Rolipram and/or pentoxifylline significantly attenuated sensory dysfunction by modulating nociceptive threshold. Rolipram and/or pentoxifylline treatment dramatically increased the cAMP level, prevented mitochondrial dysfunction, apoptosis and degeneration of DRG neurons, which appears to be mediated by inducing ATP and MMP, improving cytochrome c release, as well as regulating the expression of Bax, Bcl-2, and caspase-3 proteins, and improving morphological abnormalities of DRG neurons. We found maximum effectiveness with rolipram and pentoxifylline combination on mentioned factors. These findings encourage the use of rolipram and pentoxifylline combination as a novel experimental evidence for further clinical investigations in the treatment of DN.