Effects of sympathectomy on the cutaneous temperature abnormalities in rats with chronic constriction injury of the sciatic nerve.

Effects of surgical sympathectomy on the cutaneous temperature abnormalities of plantar surface evoked by the chronic constriction injury (CCI) of the sciatic nerve were investigated in the rat. In normal animals, there were very small temperature differences between both plantar surfaces. There were also very small temperature differences in plantar surfaces following the sympathectomy prior to CCI. In rats with CCI, the cutaneous temperature of the nerve-injured plantar surface was significantly higher (warmer) than that of the contralateral plantar surface during the first week following CCI, and then became lower (cooler). Surgical sympathectomy prior to and just after CCI significant suppressed the temperature abnormalities during the first week, but no effect was observed after 2 weeks following CCI. These observations indicate that sympathetic vasoconstriction may contribute to the cutaneous temperature abnormalities evoked by CCI during the early stage, but does not affect the abnormalities at later stages.