OBJECTIVETo investigate the mechanism of epididymal hypofunction of rats with varicocele (VC) by observing the changes in the epididymal index, motility of epididymal sperm, expressions of hypoxia-inducible factor 1 alpha (HIF-1 alpha) and the tumor suppressor protein p53, and epididymal epithelial cells.

METHODSNinety SD rats were equally randomized to a VC model (A), a sham operation (B), and a normal control group (C). At 49 days after surgery, all the rats were executed after weighing. Then the volume of the left epididymis was obtained, the epididymal sperm motility was detected by computer-assisted sperm analysis (CASA), the expressions of HIF-1 alpha and p53 in the epididymal tissue were determined by Western-blot, and the epididymal epithelial cells were observed by HE staining.

RESULTSVC models were successfully established in 27 of the rats. One-way ANOVA test showed no statistically significant differences in the epididymis index among groups A ([40.53 +/- 1.76] x 10 (-5)) , B ([43.31 1.58] x 10( -5)) , and C ( [44. 10 +/- 2.62] x 10 -5) (P > 0.05). Sperm motility and the percentage of progressively motile sperm were significantly lower in group A ([71.86 +/- 5.07]% and [42. 26 +/-4.45]%) than in B ([78.51 4.50]% and [49.08 +/-4. 19]% ) and C ( [79.24 +/- 2.70] % and [52. 23+/- 2. 23] % ) (both P <0.05) , while the expressions of HTF-1 a and p53 were remarkably higher in A (1.74 +/- 0. 16 and 1.71 +/- 0. 11) than in B (0.32 +/- 0. 08 and 0.56 +/- 0.13) and C (0.12 +/- 0. 03 and 0.25 +/-0.06) (both P < 0.05). The epididymal epithelial cells in group A were obviously decreased in number and arranged in loose and disorderly patterns as compared with those in B and C.

CONCLUSIONVaricocele can cause hypoxia in the epididymal tissue, which in turn may lead to epididymal hypofunction.