Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Int J Urol. 2013 Oct;20(10):1024-31. doi: 10.1111/iju.12100. Epub 2013 Feb 5.
Long-term ketamine abuse can affect the urinary system, resulting in interstitial cystitis-like syndrome. However, its pathogenesis remains unclear. In the present study, a proteomic approach of two-dimensional difference gel electrophoresis followed by matrix-assisted laser desorption/ionization time-of-light mass spectrometry was carried out to investigate the potential disease-associated proteins in a rat model of ketamine-associated cystitis.
Rats were randomly assigned to control, normal saline, low dose of ketamine (10 mg/kg) and high-dose of ketamine (50 mg/kg) groups with six rats in each group. The two experimental groups were given ketamine hydrochloride i.p. daily, whereas the normal saline group rats were treated with saline. After 16 weeks of treatment, all bladders were excised, and samples from normal saline and high dose of ketamine groups were resolved in two-dimensional difference gel electrophoresis. Differentially expressed spots were excised and identified by matrix-assisted laser desorption/ionization time-of-light mass spectrometry. Phosphoprotein and non-phosphoprotein purification, histopathology, immunohistochemistry, and western blot were carried out in all groups.
Histological study showed hyperplastic epithelium and inflammatory cells infiltration in the high dose of ketamine-treated rat bladders. Two-dimensional difference gel electrophoresis revealed 30 altered expressions between the normal saline and high dose of ketamine-treated group. Among these proteins, two upregulated and two downregulated protein spots were all identified as smooth muscle protein-22/transgelin. Immunohistochemical staining and western blot analysis showed that the expression of total transgelin had no significant difference between groups. However, the expression of phosphorylated transgelin in the low-dose and high dose of ketamine groups was increased, whereas the non-phosphorylated transgelin was decreased when compared with the normal saline group.
Long-term ketamine abuse induces phosphorylation of transgelin in the bladder wall, and this might play an important role in the pathogenesis of ketamine-associated cystitis.
长期滥用氯胺酮可影响泌尿系统，导致类似间质性膀胱炎的综合征。但其发病机制尚不清楚。本研究采用二维差异凝胶电泳结合基质辅助激光解吸/电离飞行时间质谱技术，对氯胺酮相关性膀胱炎大鼠模型中的潜在疾病相关蛋白进行了研究。
大鼠随机分为对照组、生理盐水组、低剂量氯胺酮（10mg/kg）组和高剂量氯胺酮（50mg/kg）组，每组 6 只。实验组大鼠腹腔注射盐酸氯胺酮，生理盐水组大鼠给予生理盐水。治疗 16 周后，切除所有膀胱，将生理盐水组和高剂量氯胺酮组的样本进行二维差异凝胶电泳分析。采用基质辅助激光解吸/电离飞行时间质谱技术对差异表达的斑点进行鉴定。对所有组进行磷酸化蛋白和非磷酸化蛋白纯化、组织病理学、免疫组织化学和 Western blot 分析。
组织学研究显示，高剂量氯胺酮处理的大鼠膀胱上皮增生和炎症细胞浸润。二维差异凝胶电泳显示，生理盐水组和高剂量氯胺酮组之间有 30 个差异表达。在这些蛋白中，有 2 个上调和 2 个下调的蛋白斑点均被鉴定为平滑肌蛋白-22/转谷氨酰胺酶。免疫组织化学染色和 Western blot 分析显示，各组间总转谷氨酰胺酶的表达无显著差异。然而，低剂量和高剂量氯胺酮组的磷酸化转谷氨酰胺酶表达增加，而非磷酸化转谷氨酰胺酶表达减少，与生理盐水组相比。
长期滥用氯胺酮诱导膀胱壁中转谷氨酰胺酶的磷酸化，这可能在氯胺酮相关性膀胱炎的发病机制中起重要作用。
