Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan.
Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan.
Mol Pain. 2024 Jan-Dec;20:17448069241261940. doi: 10.1177/17448069241261940.
This study investigated the ERK pathway of the peripheral nervous system and discovered a gender-specific pattern of ERK activation in the dorsal root ganglion of an acid-induced chronic widespread muscular pain model. We employed a twice acid-induced chronic musculoskeletal pain model in rats to evaluate mechanical pain behavior in both male and female groups. We further conducted protein analysis of dissected dorsal root ganglions from both genders. Both male and female rats exhibited a similar pain behavior trend, with females demonstrating a lower pain threshold. Protein analysis of the dorsal root ganglion (DRG) showed a significant increase in phosphorylated ERK after the second acid injection in all groups. However, phosphorylation of ERK was observed in the dorsal root ganglion, with higher levels in the male ipsilateral group compared to the female group. Moreover, there was a no difference between the left and right sides in males, whereas the significant difference was observed in females. In conclusions, the administration of acid injections induced painful behavior in rats, and concurrent with this, a significant upregulation of pERK was observed in the dorsal root ganglia, with a greater magnitude of increase in males than females, and in the contralateral side compared to the ipsilateral side. Our findings shed light on the peripheral mechanisms underlying chronic pain disorders and offer potential avenues for therapeutic intervention.
本研究调查了周围神经系统的 ERK 通路，并在酸诱导的慢性广泛性肌肉疼痛模型的背根神经节中发现了 ERK 激活的性别特异性模式。我们在大鼠中使用了两次酸诱导的慢性肌肉骨骼疼痛模型，以评估男性和女性组的机械性疼痛行为。我们进一步对来自两性的解剖背根神经节进行了蛋白质分析。雄性和雌性大鼠均表现出相似的疼痛行为趋势，而雌性大鼠的疼痛阈值较低。背根神经节（DRG）的蛋白质分析显示，所有组在第二次酸注射后 ERK 的磷酸化都显著增加。然而，在背根神经节中观察到 ERK 的磷酸化，雄性同侧组的磷酸化水平明显高于雌性组。此外，雄性的左右两侧没有差异，而雌性则存在显著差异。总之，酸注射给药会在大鼠中引起疼痛行为，同时在背根神经节中观察到 pERK 的显著上调，雄性的上调幅度大于雌性，并且在对侧侧比同侧侧更大。我们的发现揭示了慢性疼痛障碍的外周机制，并为治疗干预提供了潜在途径。
