Background

The choroid plexus (CP) is the principal source of cerebrospinal fluid (CSF). It can produce and release a wide range of materials, including growth and neurotrophic factors which have a crucial role in the maintenance and proper functioning of the brain. Tramadol is a synthetic analog of codeine, mainly prescribed to alleviate mild to moderate pains. Nevertheless, it causes several side effects, such as emotional instability and anxiety.

Methods

In this study, we focused on alterations in the expression of inflammatory and apoptotic genes in the CP under chronic tramadol exposure. Herein, rats were treated daily with tramadol at 50 mg/kg doses for three weeks. CSF samples were collected, with superoxide dismutase (SOD) and glutathione (GSH) measured in the CSF.

Results

We found that tramadol reduced the SOD and GSH levels in the CSF. Furthermore, the stereological analysis revealed a significant increase in the CP volume, epithelial cells, and capillary number upon tramadol administration. Tramadol elevated the number of blob mitochondria in CP. Also, we observed the upregulation of inflammatory and apoptosis genes following tramadol administration in the CP.

Conclusions

Our findings indicate that tramadol induces neurotoxicity in the CP via apoptosis, inflammation, and oxidative stress.

中文翻译：

---

曲马多诱导大鼠脉络丛凋亡、炎症和氧化应激

背景

脉络丛（CP）是脑脊液（CSF）的主要来源。它可以产生和释放多种物质，包括生长因子和神经营养因子，这些因子在大脑的维持和正常功能中发挥着至关重要的作用。曲马多是可待因的合成类似物，主要用于缓解轻度至中度疼痛。然而，它会引起一些副作用，例如情绪不稳定和焦虑。

方法

在这项研究中，我们重点关注慢性曲马多暴露下CP中炎症和凋亡基因表达的变化。在此，大鼠每天接受 50 mg/kg 剂量的曲马多治疗，持续三周。收集脑脊液样本，并测量脑脊液中的超氧化物歧化酶（SOD）和谷胱甘肽（GSH）。

结果

我们发现曲马多降低了脑脊液中的 SOD 和 GSH 水平。此外，体视学分析显示给予曲马多后CP体积、上皮细胞和毛细血管数量显着增加。曲马多增加了 CP 中线粒体斑点的数量。此外，我们还观察到在 CP 中给予曲马多后炎症和凋亡基因的上调。

结论

我们的研究结果表明，曲马多通过细胞凋亡、炎症和氧化应激诱导 CP 神经毒性。