Increased expression of hypoxia-inducible factor-1alpha in the internal spermatic vein of patients with varicocele

Abstract

Purpose: Varicocele is recognized as a cause of male infertility. Testis hypoxia may be one of the possible mechanisms of varicocele. We examined whether tissue hypoxia occurred in the ISV of patients with varicocele by detecting the expression of HIF-1alpha.

Materials and methods: The study group consisted of 8 patients with grade 3 left varicocele. The control group consisted of 6 volunteers with left indirect inguinal hernia. Using a left inguinal surgical incision, a 1 cm section of ISV was resected from each patient in both groups as specimens for immunoblotting and immunohistochemical staining of HIF-1alpha. Results were analyzed using Student's t test.

Results: HIF-1alpha immunoblots from both groups revealed a single band. The relative intensity of the HIF-1alpha protein band was 10.92 +/- 2.70 in the control group and 73.15 +/- 8.93 in patients with varicocele (ie 7-fold higher).

Conclusions: HIF-1alpha expression in the ISV of patients with varicocele was significantly higher than in the control group. This directly shows that hypoxia related pathophysiological changes have occurred in the ISV of patients with varicocele and that hypoxia may have also occurred in the testicular tissue. Thus, it would be of interest to investigate whether decreasing HIF-1alpha activation and testis hypoxia could reduce the recurrence of varicocele. To our knowledge, this is the first report on HIF-1alpha expression in human ISV. Additional studies will be necessary to clarify the relationship between testis hypoxia and male infertility in patients with varicocele.