Altered expression of interstitial cells of cajal in primary obstructive megaureter

ABSTRACTALTERED EXPRESSION OF INTERSTITIAL CELLS OF CAJAL IN PRIMARYOBSTRUCTIVE MEGAURETERYeliz KartDepartmant of Pediatric Surgery, Dokuz Eylül Universitiy, Medical School, , İzmir,TurkeyIntroduction and Aim: Primary obstructive megaureter is a common cause of obstructiveuropathy among neonates and young children. Characteristic features of primary obstructivemegaureter are; proksimal ureteral dilatation in variable degree, aperistaltic distal ureter 0.5-4cm and absance of vesicoureteral reflux. Many studies have investigated the etiology ofprimary obstructive megaureter and ureteropelvic junction obstruction with using electron andlight microscopy. There are controversies about the increase of the connective tissue in themusculer layer of the ureteral wall. Some investigators suggested that increase in theconnective tissue causes to obstruction by preventing the dilatation of the ureter duringdiuresis.Interstitial cells of Cajal are common pacemaker cells in human peristaltic organs thatwere first described in the gastrointestinal tract. An abscence of decrease in the number ofthese cells has been implicated in peristaltic dysfunction. Interstitial cells of Cajal in thehuman urinary tract was first described by Solary in 2003. In this study they suggested that incongenital ureteropelvic junction obstruction the number of interstitial cells of Cajal weredecreased or absent. In our study we evaluated expression of interstitial cells of Cajal inchildren with primary obstructive megaureter, normal children and fetuses.Materials and Methods: Presence of interstitial cells of Cajal evaluated withimmunohistochemical method in 11 patients who were operated because of primaryobstructive megaureter. For control group specimens were taken from the autopsies ofchildren who had died of other causes. The ureterovesical junction specimens of the fetusgroup were obtained from the aborted fetuses which were evaluated in the department ofpathology.7Results: Interstitial cells of Cajal in the ureteral wall had morphological features similar tointerstitial cells of Cajal in the gastrointestinal tract. In primary obstructive megaureter thenumber of interstitial cells of Cajal is decreased compared with normal ureter.Conclusion: In primary obstructive megaureter the number of interstitial cells of Cajal isdecreased or absent. It may be causative factor for development of primary obstructivemegaureter.Key words: Primary obstructive megaureter, interstitial cells of cajal, c-kit8