Immunohistochemical and electron microscopic examination of Cajal cells in ureteropelvic junction obstruction

Abstract

Objective: We examine the ultrastructural configurations of Cajalcells by electron microscopy, as well as the quantitative changesoccurring in Cajal cells by light microscopy.Methods: In total, 35 patients with ureteropelvic junction (UPJ)obstruction and 7 patients without obstruction were comparedimmunohistochemically with c-kit (CD117) to quantify the numberof cells. On electron microscopic examination, 7 patients with UPJobstruction and 3 patients without obstruction were compared toevaluate the changes which occurred in the ultrastructural configurationof the Cajal cells.Results: On light microscopic examination, it was determined thatthe Cajal cells, which demonstrate c-kit (CD117) immunoreactivecharacter, were located near the circular muscle layer and parallelto the muscle cells. The number of Cajal cells in the control groupwas significantly increased compared to the number of cells inpatients with UPJ obstruction (p < 0.001). On electron microscopicexamination, the number of interstitial cells was also higher in thecontrol group. A decrease in the number of the caveolae in thesecells was seen in the group with UPJ obstruction compared to thecontrol group.Conclusion: In UPJ obstruction, a decrease in the number of Cajalcells, as well as the changes in the morphologic structure of theCajal cells, indicates that these cells have a role in the pacemakersystem and are associated with ureteral peristalsis.