摘要
利用猫膝关节传入神经单纤维记录技术,观察了正常和炎症关节传入Ⅲ、Ⅳ类纤维对缓激肽(BK)的反应以及BK对辣椒素(CAP)反应的影响。在29只猫上共计记录了51条单纤维。其中正常关节22条,炎症关节29条。与正常关节传入纤维比较,炎症关节纤维中有自发放电的单位比例明显增多,且放电频率较高,被动运动分型以低机械阈值的纤维居多,CAP兴奋的阈值也较正常为低。部分纤维在使用BK后,自发放电明显增加。无论在正常还是炎症关节,被BK兴奋的单纤维中约有1/3不被CAP兴奋,而CAP兴奋的纤维则几乎全部可为BK激活,BK兴奋伤害性传入纤维的选择性不如CAP。结果提示:(1)BK可以使关节传入纤维致敏,使其对化学刺激剂CAP反应增强,并可使部分对CAP无反应的单位出现对CAP的反应;(2)炎症造成的致敏背景是外源性炎症介质易化感受器反应的重要条件;(3)对BK的反应性是纤维被BK致敏的一个条件。
Fifty-one fine single fibers of group Ⅲ (conduction velocity 2.5-20 m/s) and group Ⅳ (<2.5 m/s) from the normal and inflamed joints of cats were used to study the response of the joint receptors to bradykinin (BK) and the effect of BK on the response of receptors to capsaicin (CAP). As compared with the fibers from the normal joints, the percentage of units with background discharges from the inflamed joints increased obviously, especially those with high frequency discharges. Most units were excited by light to moderate mechanical stimuli by the passive movement test. The threshold of CAP required to activate these units also decreased. Of the 22 fibers from the normal joints, 20 could be activated by BK at doses of 0.26-26 μg. Of these, 13 could also be activated by CAP 10-6mol / L-10-4mol / L. Three fibers responded to CAP more intensely after intra-arterial administration of BK. The response to 10-4mol / L CAP in 2 of 7 fibers which were previously unresponsive to CAP of the same dose was induced after the injection of 26μg BK. Twenty-four of 29 fibers from the inflamed joints could be activated by BK at doses of 2.6-26μg. Of 15 fibers, which could be elicited both by BK and CAP, the response to CAP in 14 was potentiated when BK was applied. Three of 9 fibers unresponsive to CAP previously were excited by CAP after BK. The increase in background activity was observed in part of the fibers. Of the fibers both from the normal and the inflamed knee joints, about 1/3 elicited by BK showed no response to CAP. However, almost all fibers responsive to CAP could be activated by BK. It seems that CAP stimulates the nociceptors more selectively than BK. The results suggest that BK can sensitize the receptors of the joint fine afferent fibers, increase their response to the chemical irritant and induce the response of some fibers to CAP, which do not respond to CAP previously.The sensitization resulting from the inflammation is an important condition for the exogenous inflammatory mediator to facilitate the react
出处
《中国应用生理学杂志》
CAS
CSCD
1993年第1期44-49,共6页
Chinese Journal of Applied Physiology
关键词
传入神经纤维
炎症
缓激肽
afferent nerve fiber
inflammation
bradykinin
chemoreceptor
