title: Recovery of colonic transit following extrinsic nerve damage in rats.
abstract: BACKGROUND
  Injury to pelvic sympathetic and parasympathetic nerves from surgical and obstetrical trauma has long been cited as a cause for abnormal colorectal motility in humans. Using a rat model, acute transaction of these extrinsic nerves has been shown to effect colorectal motility. The aim of this study is to determine in a rat model how transection of these extrinsic nerves affects colonic transit over time.
  
  
  METHODS
  Eighty-two Sprague-Dawley rats underwent placement of a tunneled catheter into the proximal colon. Bilateral hypogastric, pelvic nerves (HGN and PN) or both were transected in 66 rats. The remaining 16 rats received a sham operation. Colonic transit was evaluated at postoperative days (PODs) 1, 3, and 7 by injecting and calculating the geometric center (GC) of the distribution of (51)Cr after 3 h of propagation.
  
  
  RESULTS
  At POD 1, transection of PNs significantly delayed colonic transit (GC = 4.9, p < 0.05), while transection of HGNs (GC = 8.5, p < 0.05) or transection of both nerves (GC = 7.8, p < 0.05) significantly accelerated colonic transit, when compared with sham operation (GC = 6.0). A significant trend toward recovery was noted in both the HGN and PN transection groups at POD 7.
  
  
  CONCLUSIONS
  Damage to the extrinsic sympathetic and/or parasympathetic PNs affects colonic transit acutely. These changes in large bowel motor function normalize over time implicating a compensatory mechanism within the bowel itself.
authors.affiliation: Department of Surgery, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Ridolfi
authors.forename: Wei Dong
authors.initials: WD
authors.lastname: Tong
authors.forename: Lauren
authors.initials: L
authors.lastname: Kosinski
authors.forename: Toku
authors.initials: T
authors.lastname: Takahashi
authors.forename: Kirk A
authors.initials: KA
authors.lastname: Ludwig
mesh_terms: D000818:Animals; D003106:Colon / Q000502:physiology*; D004195:Disease Models, Animal; D005772:Gastrointestinal Transit / Q000502:physiology*; D007001:Hypogastric Plexus / Q000293:injuries*; D008297:Male; D010275:Parasympathetic Nervous System / Q000293:injuries*; D010388:Pelvis / Q000294:innervation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function; D020196:Trauma, Nervous System / Q000503:physiopathology*