TY - JOUR
T1 - Peripheral capsaicin receptors increase in the inflamed rat hindpaw
T2 - A possible mechanism for peripheral sensitization
AU - Carlton, Susan M.
AU - Coggeshall, Richard E.
N1 - Funding Information:
The authors thank Zhixia Ding for assistance in the immunohistochemistry and electron microscopy and Vicki Wilson for her excellent secretarial assistance. This work was supported by NIH NS27910 and NS11255 to S.M.C, NS1061 to R.E.C., and NS40700 to S.M.C. and R.E.C.
PY - 2001/9/7
Y1 - 2001/9/7
N2 - The vanilloid receptor-1 (VR1) is activated by capsaicin, heat and protons and is localized on primary sensory neurons. The present study investigates whether VR1 increases in the inflamed hindpaw thereby contributing to the peripheral sensitization and heat hyperalgesia that characterizes the inflamed state. Forty-eight hours after intraplantar injection of Complete Freund's Adjuvant into one hindpaw, there is a significant increase in the proportion of VR1-labeled unmyelinated axons in digital nerves in the inflamed (32.8 ± 5.9%) compared to normal (17.1 ± 2.6%) hindpaws (t-test, P < 0.01). A few, small diameter myelinated axons are labeled in normal and inflamed rats with no change in percentages following inflammation. The data suggest that an increase in number of unmyelinated sensory axons expressing VR1 may be one mechanism underlying peripheral sensitization of nociceptors in inflammation.
AB - The vanilloid receptor-1 (VR1) is activated by capsaicin, heat and protons and is localized on primary sensory neurons. The present study investigates whether VR1 increases in the inflamed hindpaw thereby contributing to the peripheral sensitization and heat hyperalgesia that characterizes the inflamed state. Forty-eight hours after intraplantar injection of Complete Freund's Adjuvant into one hindpaw, there is a significant increase in the proportion of VR1-labeled unmyelinated axons in digital nerves in the inflamed (32.8 ± 5.9%) compared to normal (17.1 ± 2.6%) hindpaws (t-test, P < 0.01). A few, small diameter myelinated axons are labeled in normal and inflamed rats with no change in percentages following inflammation. The data suggest that an increase in number of unmyelinated sensory axons expressing VR1 may be one mechanism underlying peripheral sensitization of nociceptors in inflammation.
KW - Dorsal root ganglion
KW - Primary sensory neurons
KW - Thermal hyperalgesia
KW - Vanilloid
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U2 - 10.1016/S0304-3940(01)02093-6
DO - 10.1016/S0304-3940(01)02093-6
M3 - Article
C2 - 11524156
AN - SCOPUS:0035823409
SN - 0304-3940
VL - 310
SP - 53
EP - 56
JO - Neuroscience Letters
JF - Neuroscience Letters
IS - 1
ER -