Increase in muscle nociceptive substances and anaerobic metabolism in patients with trapezius myalgia: microdialysis in rest and during exercise
2004 (English)In: Pain, ISSN 0304-3959, E-ISSN 1872-6623, Vol. 112, no 3, 324-334 p.Article in journal (Refereed) Published
Local metabolic changes are suggested to be involved in muscle pain development in humans. Nineteen women with chronic work-related trapezius myalgia (TM) and 20 healthy female controls (CON) were studied during baseline rest, 20 min repetitive low-force exercise, and 120 min recovery. Interstitial serotonin (5-HT), glutamate, lactate, pyruvate, and blood flow were determined by microdialysis in the trapezius muscle. Baseline pressure pain threshold (PPT) was lower (143+/-18 (TM) vs. 269+/-17 (CON) kPa) (mean +/- SEM), pain intensity (visual analogue scale, VAS) higher (33+/-5 vs. 2+/-1 mm), muscle 5-HT higher (22.9+/-6.7 vs. 3.8+/-1.3 nmol/l), and glutamate higher (47+/-3 vs. 36+/-4 mumol/l) in TM than in CON (all P<0.05), whereas muscle blood flow was similar in groups. Furthermore, muscle pyruvate was higher (180+/-15 vs. 135+/-12 mumol/l) and lactate higher (4.4+/-0.3 vs. 3.1+/-0.3 mmol/l) in TM than in CON (P<0.001). In response to exercise, VAS and glutamate increased in both TM and CON (all P<0.05). In TM only, lactate and pyruvate increased significantly (P<0.02), whereas blood flow increased to similar levels in both groups. During the initial 20 min recovery period, blood flow remained increased in TM (P<0.005) whereas it decreased to baseline levels in CON. In conclusion, patients with chronic work-related TM have increased levels of muscle 5-HT and glutamate that were correlated to pain intensity (r=0.55, P<0.001) and PPT (r=-0.47, P<0.001), respectively. In addition, TM was associated with increased anaerobic metabolism, whereas a normal rise in blood flow was seen with exercise. These findings indicate that peripheral nociceptive processes are active in work-related TM.
Place, publisher, year, edition, pages
2004. Vol. 112, no 3, 324-334 p.
lactate, pyruvate, serotonin, glutamate, muscle pain, sensitization, tension-type headache, human masseter muscle, chronic neck pain, in-vivo evidence, blood-flow, healthy controls, skeletal-muscle, female cleaners, tendon tissue, glutamate
IdentifiersURN: urn:nbn:se:kth:diva-23944ISI: 000225601500013OAI: oai:DiVA.org:kth-23944DiVA: diva2:342643
QC 201005252010-08-102010-08-10Bibliographically approved