An investigation of underlying mechanism of delayed inflammatory state and hyperalgesia located in a healed wound-A study of involvement of sympathetic activity and possibility of therapeutical effect of preemptive sympathectomy

1.预先交感神经切断可防止慢性炎症大鼠后爪的炎症变化（肿胀、发红），但不影响去甲肾上腺素对慢性炎症大鼠C-纤维伤害性感受器的增强作用。这表明在慢性炎症条件下，炎症过程的发展和伤害感受器的肾上腺素能敏感性之间的潜在机制存在根本差异。2，在神经病理性大鼠中，血浆去甲肾上腺素的每日变化有明显的发展。3.低浓度ATP（一种模拟剂量的交感神经递质）在热刺激后可兴奋部分CPRs，但随后的热反应减弱。较高浓度的ATP（模拟受损细胞的剂量）兴奋一些CPRs并增加热反应。ATP在CRPS的交感维持性痛觉过敏中似乎不起主导作用。4、慢性炎症引起的皮肤C纤维伤害性感受器对去甲肾上腺素的敏感性在刘易斯品系和Sprague-Dawley品系之间存在明显差异。提示交感神经切除术疗效的广泛性是由于个体交感神经依赖性的差异所致。

1, Preemptive sympathectomy prevented the development of inflammatory changes (swelling, redness) in the hindpaw, while but not influence the augmenting effects of noradrenaline on the C-fiber nociceptors of chronic inflamed rats. This suggests fundamental differences of underlying mechanism between developments of inflammatory process and adrenergic sensitivity of nociceptors under chronic inflamed condition.2, There was a clear development of daily change in plasma noradrenaline in rats rendered neuropathic. This suggests that sympathetic activity is not stable through the whole period of CRPS.3, Low concentration of ATP (a mimic dose of sympathetic transmitter) excited some of the CPRs after heat stimulations, but the subsequent heat responses were decreased. Higher concentration of ATP (a mimic dose of damaged cell) excited some CPRs and increased the heat responses. ATP seems not to have a predominant role in the sympathetically maintained hyperalgesia in CRPS.4, There were clear differences between the Lewis strain and Sprague-Dawley rate in chronic inflammation induced noradrenaline sensitivity of cutaneous C-fiber nociceptors. This suggests that wide rage of therapeutic effect of sympathectomy is due to difference of sympathetic dependency of each subject.