dynorphins and Fibromyalgia

The neurophysiologic term allodynia has been applied to fibromyalgia because people with that disorder experience pain from pressure stimuli which are not normally painful. The nociceptive neurotransmitters of animal studies are now relevant to this human model of chronic, widespread pain. Evidence is presented to implicate several chemical pain mediators (including serotonin, substance P, nerve growth factor, and dynorphin A) in the pathogenesis of fibromyalgia. This perception is hopeful because it offers many new options for the development of innovative therapy.

Topics: Analgesia; Animals; Calcitonin Gene-Related Peptide; Dynorphins; Fibromyalgia; Humans; Hyperalgesia; Neurotransmitter Agents; Serotonin; Substance P

The CSF levels of Met-enkephalin-Arg6-Phe7 and dynorphin A were measured in patients with fibromyalgia. The mean CSF Met-enkephalin-Arg6-Phe7 level was 35.1 +/- 2.4 fmol/ml (mean +/- S.E.M.). The mean CSF level of dynorphin A was 14.3 +/- 0.9 fmol/ml. Regression analysis showed a statistically significant correlation between Met-enkephalin-Arg6-Phe7 and dynorphin A (r = 0.5369, P = 0.001). When correlated to the previously measured CSF levels of beta-endorphin, a statistically significant correlation was found with Met-enkephalin-Arg6-Phe7 (r = 0.5055, P = 0.03) but not with dynorphin A (P greater than 0.05). The Met-enkephalin-Arg6-Phe7 and dynorphin A levels are elevated compared to the levels available for comparison groups. Therefore, a lack of endorphin secretion does not seem to be the basis for the hyperalgesia observed in these patients.

Topics: Adult; Biomarkers; Dynorphins; Endorphins; Enkephalin, Methionine; Female; Fibromyalgia; Humans; Radioimmunoassay; Regression Analysis