Kim Sok Ho, Kwon Jung Kee, Kwon Young Bae
Department of Laboratory Animal Medicine, College of Veterinary Medicine, Chonbuk National University, Jeonju, Korea.
Lab Anim Res. 2012 Jun;28(2):131-6. doi: 10.5625/lar.2012.28.2.131. Epub 2012 Jun 26.
Pain symptoms are a common complication of diabetic peripheral neuropathy or an inflammatory condition. In the most experiments, only one or two evident pain modalities are observed at diabetic peripheral neuropathy according to experimental conditions. Following diabetic peripheral neuropathy or inflammation, spinal glial activation may be considered as an important mediator in the development of pain. For this reason, the present study was aimed to address the induction of pain modalities and spinal glial expression after streptozotocin injection as compared with that of zymosan inflammation in the rat. Evaluation of pain behavior by either thermal or mechanical stimuli was performed at 3 weeks or 5 hours after either intravenous streptozotocin or zymosan. Degrees of pain were divided into 4 groups: severe, moderate, mild, and non-pain induction. On the mechanical allodynia test, zymosan evoked predominantly a severe type of pain, whereas streptozotocin induced a weak degree of pain (severe+moderate: 57.1%). Although zymosan did not evoke cold allodynia, streptozotocin evoked stronger pain behavior, compared with zymosan (severe+moderate: 50.0%). On the other hand, the high incidence of thermal hyperalgesia (severe+moderate: 90.0%) and mechanical hyperalgesia (severe+moderate: 85.7%) by streptozotocin was observed, as similar to that of zymosan. In the spinal cord, the increase of microglia and astrocyte was evident by streptozotocin, only microglia was activated by zymosan. Therefore, it is recommended that the selection of mechanical and thermal hyperalgesia is suitable for the evaluation of streptozotocin induced diabetic peripheral neuropathy. Moreover, spinal glial activation may be considered an important factor.
疼痛症状是糖尿病性周围神经病变或炎症性疾病的常见并发症。在大多数实验中，根据实验条件，在糖尿病性周围神经病变中仅观察到一两种明显的疼痛模式。糖尿病性周围神经病变或炎症后，脊髓胶质细胞激活可能被认为是疼痛发生发展的重要介质。因此，本研究旨在探讨链脲佐菌素注射后与酵母聚糖诱导的大鼠炎症相比，疼痛模式的诱导及脊髓胶质细胞表达情况。在静脉注射链脲佐菌素或酵母聚糖后3周或5小时，通过热刺激或机械刺激对疼痛行为进行评估。疼痛程度分为4组：重度、中度、轻度和无疼痛诱导。在机械性异常性疼痛试验中，酵母聚糖主要诱发重度疼痛，而链脲佐菌素诱发的疼痛程度较轻（重度+中度：57.1%）。虽然酵母聚糖未诱发冷异常性疼痛，但与酵母聚糖相比，链脲佐菌素诱发的疼痛行为更强（重度+中度：50.0%）。另一方面，观察到链脲佐菌素引起的热痛觉过敏（重度+中度：90.0%）和机械性痛觉过敏（重度+中度：85.7%）的发生率较高，与酵母聚糖相似。在脊髓中，链脲佐菌素可明显增加小胶质细胞和星形胶质细胞数量，而酵母聚糖仅激活小胶质细胞。因此，建议选择机械性和热痛觉过敏来评估链脲佐菌素诱导的糖尿病性周围神经病变。此外，脊髓胶质细胞激活可能是一个重要因素。
