HIF-1alpha, iNOS and VEGF Expression of Contralateral Kidney during Acute Stage in Complete Ureteral Obstruction of Rat Model / 대한비뇨기과학회지

Purpose: To understand the process of hemodynamic change and compensatory hypertrophy of the contralateral kidney in an acute ureteral obstruction (UO), the inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1alpha (HIF-1alpha) expressions in the contralateral kidney were evaluated during the acute stage of unilateral UO in the rat. Materials and Methods: Specimens (kidneys) were aseptically removed from 35 Sprague-Dawley rats (8 weeks old, weight 250-300gm) of the control (0 hours), sham (6, 12 and 24 hours) and experimental groups (UO 6, 12 and 24 hours). The iNOS, VEGF and HIF-1alpha expressions in the contralateral kidney (total renal tissue, medulla and cortex) were evaluated by immunohistochemical staining. The HIF-1alpha expression was also evaluated by a Western blot assay. Results: Contrary to the control and sham groups, the iNOS, VEGF and HIF-1alpha expressions in the contralateral kidney from the immunohistochemical staining increased with time of obstruction, especially in the medulla. The HIF-1alpha expression in the contralateral kidney by the Western blot assay was increased in all the renal tissue, medulla and cortex compared to those in the control and sham groups. Conclusions: In the contralateral kidneys of rats with UO increased expressions of iNOS, VEGF and HIF-1alpha may facilitate trophic changes and a compensatory increase in the blood flow.

Hypoxic Damage in the Contralateral Testis after Unilateral Testicular Torsion in a Rat Model: Hemodynamic Change and Expressions of Hypoxia Inducible Factor-1alpha, VEGF and Apoptosis in the Contralateral Testis / 대한비뇨기과학회지

PURPOSE: The present study aimed to evaluate the hypoxic damage in the contralateral testis after unilateral testicular torsion in a rat model, using hemodynamic change, the expression of hypoxia inducible factor-1alpha(HIF-1alpha) and apoptosis. MATERIALS AND METHODS: Thirty-five male albino Sprague-Dawley rats were randomly divided into 7 groups: 0 and 6 hours after sham operations, 6, 12 and 24 hours, and 3 and 7 days after the unilateral testicular torsion. Torsion was created by rotating the left testis 720 degrees, in a clockwise direction, which was maintained by fixing the testis to the scrotum with a silk suture. The testicular blood flow of the contralateral testis was measured by laser flowmetry, both before and after the testicular torsion. After bilateral orchiectomies had been performed in each group, the expressions of HIF-1alpha and vascular endothelial growth factor (VEGF), as well as apoptosis were determined by immunohistochemical staining and Western blot analysis. RESULTS: The blood flow of the contralateral testis after the unilateral testicular torsion significantly decreased compared with that of the sham group (p<0.05). In the immunohistochemical staining, the expression of HIF-1alpha protein increased in the testicular torsion group compared to that of the sham group, and was markedly apparent 12 hours after the testicular torsion. The apoptotic cell index was also significantly higher in the testicular torsion group than in the sham group (p<0.05). In the Western blot study, the HIF-1alpha and VEGF expressions were increased in the testicular torsion group compared to those in the sham group 6 hours after the testicular torsion. CONCLUSIONS: This study suggests that the decreased testicular blood flow of the contralateral testis during ipsilateral testicular torsion induces HIF-1alpha, resulting in apoptosis of germ cells.