Role of an endothelin type A receptor antagonist in regulating torsion-induced testicular apoptosis in rats
Sevil Cayli1, Seda Ocakli2, Ufuk Senel3, Zafer Karaca2, Fikret Erdemir4 and Tuncay Delibasi5,6
1Department of Histology and Embryology, Faculty of Medicine, Yildirim Beyazit University, Ankara, 2Department of Histology and Embryology, Faculty of Medicine, Gaziosmanpasa University, Tokat, 3Department of Pediatric Surgery, Faculty of Medicine, Gaziosmanpasa University, Tokat, 4Department of Urology, Faculty of Medicine, Gaziosmanpasa University, Tokat, 5Department of Endocrinology and Metabolism, Diskapi Teaching and Research Hospital, Ankara and 6Department of Internal Medicine, School of Medicine (Kastamonu), Hacettepe University, Turkey
Offprint requests to: Sevil Cayli, Assosc. Prof. Dr., Department of Histology and Embryology, Faculty of Medicine, Yildirim Beyazit University, Ankara, Turkey. e-mail: sevilcayli@yahoo.com
Summary. Testicular torsion is a well-known medical emergency that can lead to pathological changes in the testicular tissues and male infertility. This investigation was undertaken to gain insight into the effects of an endothelin type A receptor antagonist (BQ123) on torsion-induced germ cell loss. Twenty-eight male Wistar albino rats were divided into four groups. In group I (control group), a sham operation to the left testis was performed. In group II (I/R injury), I/R injury was created by rotating the left testis 720° in a clockwise direction for 2 h and detorsing the testis after 2 h. In group III (I/R injury+BQ123), the rats were subjected to I/R injury and BQ123 injection (1 mg/kg, intravenous). In group IV (control+BQ123), the sham operated rats were subjected to BQ123. The testes of the rats were removed in all groups. Torsion-induced apoptosis and the effects of BQ123 were examined by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end labelling (TUNEL) technique, immunohistochemistry and western blotting. In group II, the number of TUNEL-positive cells increased after testicular torsion. Immunohistochemistry and western blotting showed that apoptotic proteins (active caspase 3 and Bax) were upregulated, and the anti-apoptotic protein Bcl2 was downregulated in I/R injury. The administration of BQ123 caused a significant decrease in the number of apoptotic cells and the expression of apoptotic proteins (p<0.05) when compared with the I/R injury group. No significant effect of BQ123 was observed in the testicular cells of group IV. This animal study provides evidence of the regulatory effects of BQ123 on torsion-induced testicular apoptosis. Histol Histopathol 31, 585-594 (2016)
Key words: Apoptosis, Endothelin type A receptor antagonist, Rat, Testis, Torsion
DOI: 10.14670/HH-11-698