Serotonin, glutamate and glycerol are released after the injection of hypertonic saline into human masseter muscles - a microdialysis study
2014 (English)In: Journal of Headache and Pain, ISSN 1129-2369, E-ISSN 1129-2377, Vol. 15Article in journal (Refereed) Published
Chronic myalgia is associated with higher muscle levels of certain algesic biomarkers. The aim of this study was to investigate if hypertonic saline-induced jaw myalgia also leads to release of such biomarkers and if there were any sex differences in this respect. Healthy participants, 15 men and 15 aged-matched women (25.7 +/- 4.3 years) participated. Intramuscular microdialysis into masseter muscles was performed to sample serotonin (5-HT), glutamate, lactate, pyruvate, glucose and glycerol. After 2 hours 0.2 mL hypertonic saline (58.5 mg/mL) was injected into the masseter on one side and 0.2 mL isotonic saline (9 mg/mL) into the contralateral masseter close to the microdialysis catheter. Microdialysis continued for 1 hour after the injections. Pressure pain thresholds (PPT) and pain were assessed before and after injections. The median (IQR) peak pain intensity (0-100 visual analogue scale) after hypertonic saline was 52.5 (38.0) and after isotonic saline 7.5 (24.0) (p less than 0.05). 5-HT, glutamate and glycerol increased after hypertonic saline injection (p less than 0.05). Lactate, pyruvate and glucose showed no change. PPT after microdialysis was reduced on both sides (p less than 0.05) but without side differences. Pain after hypertonic saline injection correlated positively to 5-HT (p less than 0.05) and negatively to glycerol (p less than 0.05). 5-HT, glutamate and glycerol increased after a painful hypertonic saline injection into the masseter muscle, but without sex differences. Since increased levels of 5-HT and glutamate have been reported in chronic myalgia, this strengthens the validity of the pain model. Glycerol warrants further investigations.
Place, publisher, year, edition, pages
Springer Verlag (Germany) / SpringerOpen / BioMed Central , 2014. Vol. 15
Hypertonic saline; Pain; Masseter muscle; Biomarkers
IdentifiersURN: urn:nbn:se:liu:diva-114255DOI: 10.1186/1129-2377-15-89ISI: 000347693000001PubMedID: 25519464OAI: oai:DiVA.org:liu-114255DiVA: diva2:788617