The effects of ureteral obstruction on Cajal-like cells in rats Baris Kuzgunbay a, *, Figen Doran b , Yildirim Bayazit a , Tahsin Turunc a , Nihat Satar a , Aliye Atay Kayis c a Faculty of Medicine, Department of Urology, C ¸ukurova University, 01330 Adana, Turkey b Faculty of Medicine, Department of Pathology, C ¸ukurova University, 01330 Adana, Turkey c Faculty of Economic and Administrative Sciences, Department of Business Administration, Suleymen Demirel University, Isparta, Turkey Received 8 October 2008; accepted 7 December 2008 Available online 21 January 2009 KEYWORDS Cajal cells; c-Kit; Obstruction; Ureter Abstract Objective: To determine the changes in number and morphology of interstitial cells of Cajal (ICC)-like cells (ICC-LC) at the ureteropelvic junction (UPJ) of rats after experimental distal ureteral obstruction. Materials and methods: Of a total of 109 rats, 20 served as controls (C), 20 underwent sham- operations (SH) and 69 were in the study (S) groups. The UPJs were extracted initially in the C and SH groups, and 7, 14, 30, 60 and 90 days after ligation of the distal ureter in the study groups (S1, S2, S3, S4 and S5, respectively). The sections stained by c-kit anticore were studied under a light microscope. Results: The mean number of ICC-LC was 4.55  2.21 in C, 5.15  3.51 in SH, 7.40  6.88 in S1, 21.16  19.03 in S2, 12.63  8.16 in S3, 10.40  5.09 in S4, and 10.9  6.33 in S5. There was a statistically significant increase in ICC-LC in the study groups, except S1, compared to the C and SH groups. No significant difference was detected in Cajal cell morphology and distribu- tion pattern between groups. Conclusions: Based on the changes in number of ICC-LC at the UPJ after obstruction of the distal ureter compared with the limited data available in the literature, we suggest that ICC-LC have a close relationship with motility of the ureter. ª 2008 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved. Introduction The interstitial cells of Cajal (ICC) were first described by Ramon Y. Cajal in 1893 as primitive neurons in the gastro- intestinal system (GIS) [1]. Subsequent investigations revealed that these cells play a role as pacemaker cells * Corresponding author. Tel.: þ90 322 3386060; fax: þ90 322 3272596. E-mail address: kuzgunbay33@yahoo.com (B. Kuzgunbay). 1477-5131/$36 ª 2008 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jpurol.2008.12.006 Journal of Pediatric Urology (2009) 5, 269e273