uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Differential sensitization of silent nociceptors to low pH stimulation by prostaglandin E2 in human volunteers
Show others and affiliations
2015 (English)In: European Journal of Pain, ISSN 1090-3801, E-ISSN 1532-2149, Vol. 19, no 2, 159-166 p.Article in journal (Refereed) Published
Abstract [en]

BackgroundInflammatory mediators activate and sensitize nociceptors. Tissue acidosis with low pH of 5.5 often accompanies inflammation and could enhance inflammatory pain and sensitization. MethodsAction potentials from single mechano-responsive (CM) and mechano-insensitive (CMi) C-nociceptors of cutaneous fascicles of the peroneal nerve in healthy volunteers were recorded by microneurography. Low pH solutions with and without prostaglandin E2 (PGE2) were injected twice (with an interval of approximately 5min) into two spots of the receptive fields of C-fibres. Heat thresholds of the C-fibres were obtained before and after each injection. ResultsInjections of the low pH solutions immediately induced phasic responses in CM nociceptors, whereas CMi fibres responded after a delay of several seconds with a sustained response. More CMi fibres than CM fibres showed ongoing discharge after low pH injection, but the duration and intensity of the responses to the first low pH injection did not differ between them. Upon repetition, duration and intensity of the pH responses increased more than twofold in CMi fibres only. Furthermore, combined application of pH and PGE2 sensitized the response in CMi fibres only. In contrast, heat activation thresholds were sensitized by the combination of low pH and PGE2 in both fibre classes. ConclusionsOur results confirm nociceptor class independent heat sensitization by PGE2 which is probably mediated by transient receptor potential vanilloid 1 phosphorylation. However, prolonged and increased pain responses in humans upon low pH/PGE2 stimulation appear to be primarily dependent on CMi fibres, whereas CM nociceptors appear crucial for phasic responses.

Place, publisher, year, edition, pages
2015. Vol. 19, no 2, 159-166 p.
National Category
URN: urn:nbn:se:uu:diva-246825DOI: 10.1002/ejp.532ISI: 000348567300004PubMedID: 24890616OAI: oai:DiVA.org:uu-246825DiVA: diva2:794360
Available from: 2015-03-11 Created: 2015-03-10 Last updated: 2015-03-11Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Schmidt, Roland
By organisation
Clinical Neurophysiology
In the same journal
European Journal of Pain

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 149 hits
ReferencesLink to record
Permanent link

Direct link