title: Cold-induced vasodilatation in cold-intolerant rats after nerve injury.
abstract: OBJECTIVE
  Cold-induced vasodilatation (CIVD) is a cyclic regulation of blood flow during prolonged cooling of protruding body parts. It is generally considered to be a protective mechanism against local cold injuries and cold intolerance after peripheral nerve injury. The aim of this study was to determine the role of the sympathetic system in initiating a CIVD response.
  
  
  METHODS
  Eight rats were operated according to the spared nerve injury (SNI) model, eight underwent a complete sciatic lesion (CSL) and six underwent a sham operation. Prior to operation, 3, 6 and 9 weeks postoperatively, both hind limbs were cooled and the skin temperature was recorded to evaluate the presence of CIVD reactions. Cold intolerance was determined using the cold plate test and mechanical hypersensitivity measured using the Von Frey test.
  
  
  RESULTS
  No significant difference in CIVD was found comparing the lateral operated hind limb for time (preoperatively and 3, 6 and 9 weeks postoperatively; p = 0.397) and for group (SNI, CSL and Sham; p = 0.695). SNI and CSL rats developed cold intolerance and mechanical hypersensitivity.
  
  
  CONCLUSIONS
  Our data show that the underlying mechanisms that initiate a CIVD reaction are not affected by damage to a peripheral nerve that includes the sympathetic fibres. We conclude that the sympathetic system does not play a major role in the initiation of CIVD in the hind limb of a rat.
  
  
  CONCLUSIONS
  No substantial changes in the CIVD reaction after peripheral nerve injury imply that the origin of cold intolerance after a traumatic nerve injury is initiated by local factors and has a more neurological cause. This is an important finding for future developing treatments for this common problem, as treatment focussing on vaso-regulation may not help diminish symptoms of cold-intolerant patients.
authors: Department of Plastic, Reconstructive and Hand Surgery, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors: E S
authors: ES
authors: Smits
authors: L S
authors: LS
authors: Duraku
authors: S P
authors: SP
authors: Niehof
authors: H A M
authors: HA
authors: Daanen
authors: S E R
authors: SE
authors: Hovius
authors: R W
authors: RW
authors: Selles
authors: E T
authors: ET
authors: Walbeehm
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001833:Body Temperature Regulation; D003080:Cold Temperature / Q000009:adverse effects*; D004195:Disease Models, Animal; D007036:Hypothermia, Induced; D008297:Male; D059348:Peripheral Nerve Injuries / Q000503:physiopathology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D012584:Sciatic Nerve / Q000293:injuries*; D012881:Skin Temperature; D014664:Vasodilation / Q000502:physiology*
keywords: Cold intolerance; Cold stress; Cold-induced vasodilatation; Peripheral nerve injury; Rat; Vasodilatation