title: Functional evaluation of the grafted wall with porcine-derived small intestinal submucosa (SIS) to a stomach defect in rats.
abstract: BACKGROUND
  Small intestinal submucosa (SIS) represents a novel bio-scaffolding material that may be used to repair hollow-organ defects. However, it is unclear whether neurophysiologic responses return to SIS-grafted areas in the gut. We evaluated the functional recovery of a stomach defect grafted with the porcine-derived SIS.
  
  
  METHODS
  Twelve rats had a full-thickness defect created in the stomach. SIS was secured to the gastric wall. After 6 months, muscle strips were harvested from within the grafted area to perform both a histologic and a functional study. Additional full-thickness muscle strips were harvested from the posterior in the same stomach as controls. A dose response curve was obtained with carbachol (CCH) or sodium nitroprusside (SNP). Activation of intrinsic nerves was achieved by electrical field stimulation (EFS).
  
  
  RESULTS
  The response to CCH and amplitude in EFS showed tonic contraction in both controls and SIS strips in a concentration-dependent and frequency-dependent manner. The magnitude after each stimulation was significantly lower in SIS strips compared with controls (P < .01). However, the contraction ratio of EFS to ED(50) of CCH was not significantly different between the groups. Additionally, SNP produced relaxation in both strips in a concentration-dependent manner. Histologic findings revealed that an insufficient amount of smooth-muscle cells existed in the muscularis propria, whereas compensated growth was observed in the submucosa with nerve regeneration.
  
  
  CONCLUSIONS
  This study demonstrates that SIS provides a template for nerve migration to the graft in the rodent stomach. Innervations showed a similar distribution to that observed in the controls. The clinical implications of such findings warrant additional investigation.
authors.affiliation: Department of Surgery, Duke University Medical Center, Durham, NC, USA. tommy@yamaguchi-u.ac.jp
authors.forename: Tomio
authors.initials: T
authors.lastname: Ueno
authors.forename: Sebastian G
authors.initials: SG
authors.lastname: de la Fuente
authors.forename: Omar I
authors.initials: OI
authors.lastname: Abdel-Wahab
authors.forename: Toku
authors.initials: T
authors.lastname: Takahashi
authors.forename: Marcia
authors.initials: M
authors.lastname: Gottfried
authors.forename: Mary B
authors.initials: MB
authors.lastname: Harris
authors.forename: Makoto
authors.initials: M
authors.lastname: Tatewaki
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Uemura
authors.forename: D Curtis
authors.initials: DC
authors.lastname: Lawson
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Mantyh
authors.forename: Theodore N
authors.initials: TN
authors.lastname: Pappas
mesh_terms: D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002465:Cell Movement / Q000502:physiology; D018679:Cholinergic Agonists / Q000494:pharmacology; D018680:Cholinergic Antagonists / Q000494:pharmacology; D004558:Electric Stimulation; D007413:Intestinal Mucosa / Q000294:innervation / Q000473:pathology / Q000637:transplantation*; D007421:Intestine, Small / Q000294:innervation / Q000473:pathology / Q000637:transplantation*; D008297:Male; D023421:Models, Animal; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology; D009130:Muscle, Smooth / Q000502:physiology*; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000294:innervation / Q000473:pathology / Q000601:surgery*; D013552:Swine; D016378:Tissue Transplantation / Q000379:methods*; D014183:Transplantation, Heterologous / Q000379:methods
chemical_list: D018679:Cholinergic Agonists; D018680:Cholinergic Antagonists; D009599:Nitroprusside; D002217:Carbachol