HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 99/5/1977    most recent 00419.2005v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (78) Citing Articles via Google Scholar Google Scholar Articles by Shah, J. P. Articles by Gerber, L. H. Search for Related Content PubMed PubMed Citation Articles by Shah, J. P. Articles by Gerber, L. H.

INNOVATIVE METHODOLOGY

An in vivo microanalytical technique for measuring the local biochemical milieu of human skeletal muscle

¹Rehabilitation Medicine Department, Clinical Research Center, National Institutes of Health; ²Ultramicro Analytical Immunochemistry Resource, Division of Bioengineering and Physical Science, Office of Research Services, National Institutes of Health, Bethesda, Maryland; and ³Department of Exercise Science, George Washington University, Washington, DC

Submitted 14 April 2005 ; accepted in final form 11 July 2005

Myofascial pain associated with myofascial trigger points (MTrPs) is a common cause of nonarticular musculoskeletal pain. Although the presence of MTrPs can be determined by soft tissue palpation, little is known about the mechanisms and biochemical milieu associated with persistent muscle pain. A microanalytical system was developed to measure the in vivo biochemical milieu of muscle in near real time at the subnanogram level of concentration. The system includes a microdialysis needle capable of continuously collecting extremely small samples (0.5 µl) of physiological saline after exposure to the internal tissue milieu across a 105-µm-thick semi-permeable membrane. This membrane is positioned 200 µm from the tip of the needle and permits solutes of <75 kDa to diffuse across it. Three subjects were selected from each of three groups (total 9 subjects): normal (no neck pain, no MTrP); latent (no neck pain, MTrP present); active (neck pain, MTrP present). The microdialysis needle was inserted in a standardized location in the upper trapezius muscle. Due to the extremely small sample size collected by the microdialysis system, an established microanalytical laboratory, employing immunoaffinity capillary electrophoresis and capillary electrochromatography, performed analysis of selected analytes. Concentrations of protons, bradykinin, calcitonin gene-related peptide, substance P, tumor necrosis factor-, interleukin-1, serotonin, and norepinephrine were found to be significantly higher in the active group than either of the other two groups (P < 0.01). pH was significantly lower in the active group than the other two groups (P < 0.03). In conclusion, the described microanalytical technique enables continuous sampling of extremely small quantities of substances directly from soft tissue, with minimal system perturbation and without harmful effects on subjects. The measured levels of analytes can be used to distinguish clinically distinct groups.

myofascial trigger points; musculoskeletal pain; microdialysis; soft tissue pain; pressure pain threshold

This article has been cited by other articles:

				M. Siklova-Vitkova, J. Polak, E. Klimcakova, J. Vrzalova, J. Hejnova, M. Kovacikova, Z. Kovacova, M. Bajzova, L. Rossmeislova, Z. Hnevkovska, et al. Effect of hyperinsulinemia and very-low-calorie diet on interstitial cytokine levels in subcutaneous adipose tissue of obese women Am J Physiol Endocrinol Metab, November 1, 2009; 297(5): E1154 - E1161. [Abstract] [Full Text] [PDF]

				B. A. S. Borge, K.-H. Kalland, S. Olsen, A. Bletsa, E. Berggreen, and H. Wiig Cytokines are produced locally by myocytes in rat skeletal muscle during endotoxemia Am J Physiol Heart Circ Physiol, March 1, 2009; 296(3): H735 - H744. [Abstract] [Full Text] [PDF]

				S. Wang, Y. Dai, T. Fukuoka, H. Yamanaka, K. Kobayashi, K. Obata, X. Cui, M. Tominaga, and K. Noguchi Phospholipase C and protein kinase A mediate bradykinin sensitization of TRPA1: a molecular mechanism of inflammatory pain Brain, May 1, 2008; 131(5): 1241 - 1251. [Abstract] [Full Text] [PDF]