A comparative study of in vitro contractility between gut tissues of Hirschsprungs disease and other gut malformations
Anil Kumar Tiwari, Sanjeev K. Singh, Ratna Pandey, Phani Bhushan Singh, Shashikant C.U. Patne, Ajay N. Gangopadhyay, Maloy B Mandal.
Background: Hirschsprungs disease and other gut malformations commonly present with obstructive features of gut in pediatric age group. Problem of obstruction persists even after resection and anastomosis operation.
Aims and Objectives: This in vitro comparative study was performed to assess the gut contractility to chemical mediators such as Acetylcholine and Histamine between Hirschsprungs disease and other gut malformations.
Materials and Methods: The longitudinal muscle strips of Hirschsprungs cases and other gut malformations (non-Hirschsprungs cases) were placed in Dales organ bath containing Krebs-Ringer solution, continuously bobbled with 100% O2 at 28°C. Gut contractions were recorded using Power Lab 4/ST system and was analyzed using software CHART-5 for windows. Control contractions were recorded against initial tension of 0.5 g. Subsequently, agonist (acetylcholine, histamine)-induced contractions were recorded before and after appropriate antagonists (atropine, pheniramine). Before values of agonist-induced contractions of Hirschsprung and non-Hirschsprungs cases were compared. Values of agonistinduced contractions obtained after pretreatment with antagonists were also compared between Hirschsprung and non- Hirschsprungs cases.
Results: Acetylcholine enhanced contractions in non-Hirschsprungs cases and it caused small increase in amplitude of contractions in Hirschsprungs cases. Atropine pretreatment blocked acetylcholine-induced contractions significantly in non-Hirschsprungs cases, whereas it failed to block in the Hirschsprungs cases. Histamine augmented contractions in both Hirschsprung and non-Hirschsprungs cases. H1 antagonist, pheniramine failed to block the contractility in both the cases.
Conclusion: Findings of this study suggested that acetylcholine increased gut contractility significantly in non-Hirschsprungs cases involving muscarinic-cholinergic pathways, whereas histamine increased gut contractility in both Hirschsprungs disease and non-Hirschsprungs cases and it is not mediated by H1 receptors.
Key words: Gut Contractility; Hirschsprungs Disease; Gut Malformations; Acetylcholine, Histamine