Journal article
Chemosensitivity and mechanosensitivity of nociceptors from incised rat hindpaw skin
Anesthesiology (Philadelphia), Vol.111(1), pp.155-164
07/2009
DOI: 10.1097/ALN.0b013e3181a16443
PMCID: PMC2737702
PMID: 19512876
Abstract
The authors have demonstrated a decrease in pH in the incisional wound environment, suggesting a possible contribution of low pH to postsurgical pain. In this study, the authors characterized the acid-responsiveness of nociceptors innervating the plantar aspect of the rat hind paw 1 day after plantar incision and compared this to plantar skin from unincised control rats.
Using the rat glabrous in vitro skin-tibial nerve preparation, afferent nerve activities from single mechanosensitive nociceptors were recorded. Differences in mechanosensitivity, spontaneous activity, and chemosensitivity of units were evaluated. For chemosensitivity, acid-responsiveness of nociceptors to lactic acid (pH 5.5 to 6.5) was studied.
C-fibers showed dose-dependent, sustained responses to lactic acid. A greater proportion of C-fibers from 2 mm or less from the incision was activated by pH 6.0 lactic acid (52.9%) compared to control (14.3%). Total evoked potentials during acid exposure were greater in C-fibers innervating 2 mm or less from the incision compared to those in unincised skin. The prevalence of acid responses and total evoked potentials during acid exposure in C-fibers innervating more than 2 mm from the incision were not different from control. Few A-fibers responded to lactic acid, with a range of pH 5.5 to 6.5 in both incision and control groups. Increased spontaneous activity and mechanosensitivity were also evident.
C-fibers in the vicinity of the incision showed qualitatively and quantitatively greater chemosensitivity to pH 6.0 lactic acid compared to control. This change was localized to 2 mm or less from the incision, suggesting increased chemosensitivity of nociceptive C-fibers 1 day after plantar incision.
Details
- Title: Subtitle
- Chemosensitivity and mechanosensitivity of nociceptors from incised rat hindpaw skin
- Creators
- Sinyoung Kang - Department of Anesthesia, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA. sinyoung-kang@uiowa.eduTimothy J Brennan
- Resource Type
- Journal article
- Publication Details
- Anesthesiology (Philadelphia), Vol.111(1), pp.155-164
- DOI
- 10.1097/ALN.0b013e3181a16443
- PMID
- 19512876
- PMCID
- PMC2737702
- NLM abbreviation
- Anesthesiology
- ISSN
- 0003-3022
- eISSN
- 1528-1175
- Publisher
- United States
- Grant note
- R01 GM055831 / NIGMS NIH HHS R29 GM055831 / NIGMS NIH HHS GM-55831 / NIGMS NIH HHS R01 GM055831-13 / NIGMS NIH HHS
- Language
- English
- Date published
- 07/2009
- Academic Unit
- Anesthesia
- Record Identifier
- 9984007288602771
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