title: Aberrations of the intrinsic innervation of the anorectum in fetal rats with anorectal malformations.
abstract: BACKGROUND
  Fecal accumulation, constipation, soiling, and incontinence are common sequelae after repair of anorectal malformations (ARMs) in children. It is believed that besides the abnormalities of sacral roots, certain inherent abnormalities of the myenteric plexuses may play an important role in the final outcome after definitive repair.
  
  
  METHODS
  This study was conducted to investigate the distribution of neuron-specific enolase (NSE), vasoactive intestinal peptide (VIP), and substance P (SP)-100 neurotransmitters in the rectosigmoid and fistulous tract of the ethylenethiourea-treated rat with ARMs.
  
  
  RESULTS
  ARMs were induced by administering 1% ethylenethiourea (125 mg/kg) on gestational day 10, and the litter was harvested on gestational day 21 by cesarean section. Forty-eight controls and 63 with ARMs (46 high-type and 17 low-type) were recovered. Whole-mount preparations of each rectosigmoid and fistulous communication between the rectum and genitourinary tract were stained with fluorescent antibodies against NSE, VIP, and SP-100. The tissues were counterstained with Eriochrome black-T and methyl green dyes to improve the visualization of the myenteric plexuses.
  
  
  CONCLUSIONS
  The immunoreactivity of NSE, VIP, and SP-100 was markedly reduced in the rectum and fistulous tract of high-type ARMs and slightly reduced in low-type ARMs compared with controls. Intramural nerves stained by VIP and SP-100 antisera were decreased in both types of ARM, indicating that both inhibitory and excitatory motor neural elements were affected, and this may explain the distal colonic dysmotility seen postoperatively in both high and low ARMs.
authors.affiliation: Department of Paediatric Surgery, Christchurch Hospital, Christchurch 8000, New Zealand.
authors.forename: Parkash
authors.initials: P
authors.lastname: Mandhan
authors.forename: Bao Quan
authors.initials: BQ
authors.lastname: Qi
authors.forename: Spencer W
authors.initials: SW
authors.lastname: Beasley
mesh_terms: D001003:Anal Canal / Q000002:abnormalities* / Q000196:embryology / Q000294:innervation; D000818:Animals; D003248:Constipation / Q000196:embryology* / Q000209:etiology; D004065:Digestive System Abnormalities / Q000139:chemically induced / Q000150:complications; D005031:Ethylenethiourea; D005260:Female; D005333:Fetus; D007150:Immunohistochemistry; D009197:Myenteric Plexus / Q000002:abnormalities*; D018377:Neurotransmitter Agents / Q000032:analysis*; D010751:Phosphopyruvate Hydratase / Q000032:analysis; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012003:Rectal Fistula / Q000196:embryology; D012007:Rectum / Q000002:abnormalities* / Q000196:embryology / Q000294:innervation; D013373:Substance P / Q000032:analysis; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
chemical_list: D018377:Neurotransmitter Agents; D005031:Ethylenethiourea; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D010751:Phosphopyruvate Hydratase