스테로이드가 흰쥐의 신경병변성 동통 발생에 미치는 효과

초록

Objective: The purpose of this study was to evaluate the anti-inflammatory effect of steroid in the neuroma that plays a key role in the development of neuropathic pain. Method: Materials consisted of 21 male Sprague-Dawley rats (8 weeks old, 180–200 g), which were divided into a steroid (n = 9) and control group (n = 12). Neuropathic pain was produced by unilateral transection of the superior caudal trunks at the level between the S3 and S4 spinal nerves. We compared two groups of rats: the steroid group, injecting 1 ml (40 mg) of Methylprednisolone (Depo-Medrol), and the control group, injecting 1 ml of normal saline on the operation site just after operation. Behavioral reactions to mechanical allodynia were checked using von Frey hairs of 2.0 g (19.6 mN) bending force at pre-operation, post-operative 1, 4, 7, 10, and 14 days to evaluate the steroid effect on the development of neuropathic pain. Results: The steroid group exhibited less tail-flick frequencies to mechanical stimulation: 14.8 ± 17.0%, 28.1 ± 18.3%, 38.1 ± 28.3% at post-operative 4, 7, 10 days in the control group; 30.3 ± 21.2%, 43.6 ± 21.3%, 47.2 ± 20.8% at post-operative 4, 7, 10 days, respectively. But there was no significant difference between both groups at post-operative 14 days. The steroid reduced the pain at the early stage of neuropathic pain development, but failed to decrease the pain level in the late stage. Conclusion: These results suggest that the steroid-induced anti-inflammatory effect in the injured neuroma is not a key factor in the development of neuropathic pain.

키워드