Increased Expression of Hypoxia-Inducible Factor-1 alpha and Connective Tissue Growth Factor Accompanied by Fibrosis in the Rat Testis of Varicocele

Abstract

Objective: We investigated hypoxia inducible factor-1 alpha (HIF-1 alpha), connective tissue growth factor (CTGF) expression and fibrosis in the testis of rats with surgically induced varicocele. Material and methods: A total of 47 adult male Sprague-Dawley rats were arranged in 3 groups, namely group 1 (varicocele operation 4 weeks ago, n = 10; sham operation 4 weeks ago, n = 5), group 2 (8 weeks, n = 11; n = 5), and group 3 (12 weeks, n = 11; n = 5). The rats in every group underwent bilateral orchiectomy 4, 8, and 12 weeks after the operations, respectively. HIF-1 alpha and CTGF expression of both testes in group 3 were studied by real-time reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. Fibrotic change was assessed by quantitative image analysis. Results: HIF-1 alpha mRNA expression in testes tissues in varicocele operation and sham controls showed no significant differences in RT-PCR. However, CTGF mRNA expressions in left testes were found to be significantly different between varicocele operation and sham controls. HIFI a staining was present in both testes of all specimens and CTGF staining was present in 10 left and 8 right testes of 11 specimens. However HIF-1 alpha. and CTGF staining were absent in control group. There were significant fibrotic changes of both testes in groups 2 and 3. There were significant differences in fibrotic change along the durations of surgical varicocele. Conclusions: This study reveals that experimental varicocele in the rat is associated with HIF-1 alpha. and CTGF expression and it is accompanied by fibrotic change in the testis. (C) 2011 AEU. Published by Elsevier Espana, S.L. All rights reserved.