Transient receptor potential vanilloid 1-immunoreactive innervation increases in fractured rat femur.
Transient receptor potential vanilloid 1-immunoreactive innervation increases in fractured rat femur.
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DOI：
10.3349/ymj.2014.55.1.185
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发表时间：
2014-01
影响因子：
2.4
通讯作者：
Ohtori S
中科院分区：
文献类型：
--
作者：
Kawarai Y;Suzuki M;Yoshino K;Inoue G;Orita S;Yamauchi K;Aoki Y;Ishikawa T;Miyagi M;Kamoda H;Kubota G;Sakuma Y;Oikawa Y;Inage K;Sainoh T;Sato J;Nakamura J;Takaso M;Toyone T;Takahashi K;Ohtori S
椎体或股骨颈骨折引起的疼痛是临床骨科中一个特别重要的问题。瞬时受体电位香草蛋白1 （TRPV1）是一种配体门控的非选择性阳离子通道，最近有报道称骨痛与TRPV1有关。然而，股骨骨折后TRPV1活性的增加尚未见报道。我们在30只大鼠股骨上应用神经示踪剂[氟金（FG）]检测支配股骨皮质的背根神经节（DRGs）。应用后7天，行股骨骨干中段闭合性骨折。在未骨折的对照组，以及骨折后3天、1周、2周和4周，检测FG标记的trpv1免疫反应（ir） DRGs神经支配股骨。我们评估股骨的骨愈合情况，比较各时间点支配股骨的TRPV1-ir DRG神经元的比例。骨折后4周，观察到骨完全愈合。各时间点FG标记DRG神经元与总DRG神经元的比值无显著差异。骨折后第3天和第1周，股骨DRGs中TRPV1-ir神经元的百分比显著高于对照组、骨折后第2周和第4周（p<0.05）。骨折在3天内诱导支配骨折股骨的DRGs中TRPV1-ir神经元增加，在4周的骨愈合过程中减少。这些发现表明TRPV1可能在骨折疼痛的感觉感觉中起作用。
Pain from vertebral or femoral neck fractures is a particularly important problem in clinical orthopaedics. Transient receptor potential vanilloid 1 (TRPV1) is a ligand-gated nonselective cation channel, and there are recent reports on an association between bone pain and TRPV1. However, an increase in TRPV1 activity has not been reported following femoral fracture. We applied a neurotracer [Fluoro-gold (FG)] onto femur to detect dorsal root ganglia (DRGs) innervating the cortex of the femur in 30 Sprague Dawley rats. Seven days after application, a closed mid-diaphyseal fracture of the femur was performed. FG labeled TRPV1-immunoreactive (ir) DRGs innervating the femur were examined in nonfractured controls, and 3 days, 1 week, 2 weeks, and 4 weeks after fracture. We evaluated bone healing of the femur and compared the ratio of TRPV1-ir DRG neurons innervating the femur at the time points. Four weeks after fracture, complete bone union was observed. There was no significant difference in the ratio of FG labeled DRG neurons to total DRG neurons at each time point. The percentages of TRPV1-ir neurons in DRGs innervating the femur at 3 days and 1 week after fracture were significantly higher than those in control, 2 weeks, and 4 weeks after fracture (p<0.05). Fracture induced an increase of TRPV1-ir neurons in DRGs innervating the fractured femur within 3 days, and decreased during bone healing over 4 weeks. These findings show that TRPV1 may play a role in sensory sensation of bone fracture pain.