The effect of hydrocephalus on lower esophageal sphincter smooth muscle reactivity: experimental study.

PURPOSE The aim of this study was to assess the pharmacophysiological significance of the enteric nervous system for the mechanical responses of lower esophageal sphincter (LES) in infantile rats with kaolin-induced hydrocephalus. MATERIAL AND METHODS Hydrocephalus was created in 7-day-old rats by injection of kaolin into the cisterna magna. After 10 days, rats were decapitated. Contractile (KCl, carbachol) and relaxant (isoprenaline, papaverine) responses were determined by using in vitro muscle technique in isolated LES smooth muscle strips. RESULTS The receptor-mediated contractile and relaxant response to carbachol and isoprenaline in the LES smooth muscle was impaired in rats with hydrocephalus. There was no significant difference in the KCl and papaverine response in hydrocephalic and sham operated rats. CONCLUSION Our findings suggest that hydrocephalus may impair receptor-mediated contractile and relaxant activity of LES smooth muscle leading to gastroesophageal reflux.