Graven-Nielsen T, Fenger-Grøn L S, Svensson P, Steengaard-Pedersen K, Arendt-Nielsen L, Staehelin Jensen T
Center for Sensory-Motor Interaction, Laboratory for Experimental Pain Research, Aalborg University, Denmark.
Somatosens Mot Res. 1998;15(1):46-53. doi: 10.1080/08990229870943.
The aim of the present study was to study the sensibility in the area of saline-induced muscle pain. In three experiments, ten subjects were exposed to computer-controlled infusion of 0.5 ml isotonic (0.9%) or hypertonic (9%) saline into the anterior tibial muscle. The pain intensity was assessed on a visual analogue scale (VAS). The pain threshold (PT) to pressure and electrical stimulation in muscle and subcutaneous tissues was determined. Three experiments were performed in which infusion of hypertonic saline produced significantly higher VAS scores than isotonic saline. In all three experiments, there was no significant difference in PT obtained after infusion of isotonic saline compared with infusion of hypertonic saline. In experiment 1, the PT was determined at the infusion site and 4 cm from the infusion site. At the infusion site, the pressure PT decreased (-19 +/- 2%) 1, 3, 5, 7 and 9 min after infusion of isotonic and hypertonic saline, but remained unchanged 4 cm from the infusion site. The intramuscular electrical PT at the infusion site and 4 cm from the infusion site increased significantly (29 +/- 6%) 5, 7 and 9 min after saline infusion. In experiment 2, the pressure PT and the intramuscular electrical PT were recorded after two infusions of saline separated by 1 day. The day after the first infusion, the pressure PT was decreased compared with the PT before the first infusion, but the electrical PT was not affected. Moreover, the hypertonic saline infusion given on the second day produced significantly higher (130 +/- 50%) VAS scores than the infusion given on the first day. In experiment 3, the PT was determined in the subcutaneous tissue, but no significant effects of saline infusion were found. The present placebo-controlled experiments failed to show muscular or subcutaneous hyperalgesia after saline-induced muscle pain per se.
本研究的目的是研究盐水诱导的肌肉疼痛区域的敏感性。在三个实验中，10名受试者接受计算机控制的将0.5毫升等渗（0.9%）或高渗（9%）盐水注入胫骨前肌的操作。疼痛强度通过视觉模拟量表（VAS）进行评估。测定了肌肉和皮下组织对压力和电刺激的疼痛阈值（PT）。进行的三个实验中，高渗盐水输注产生的VAS评分显著高于等渗盐水。在所有三个实验中，等渗盐水输注后获得的PT与高渗盐水输注后相比无显著差异。在实验1中，在输注部位和距输注部位4厘米处测定PT。在输注部位，等渗和高渗盐水输注后1、3、5、7和9分钟，压力PT降低（-19±2%），但在距输注部位4厘米处保持不变。盐水输注后5、7和9分钟，输注部位和距输注部位4厘米处的肌肉内电PT显著增加（29±6%）。在实验2中，在两次间隔1天的盐水输注后记录压力PT和肌肉内电PT。第一次输注后的第二天，压力PT与第一次输注前相比降低，但电PT未受影响。此外，第二天给予的高渗盐水输注产生的VAS评分显著高于第一天给予的输注。在实验3中，在皮下组织中测定PT，但未发现盐水输注有显著影响。目前的安慰剂对照实验未能显示盐水诱导的肌肉疼痛本身会导致肌肉或皮下痛觉过敏。
