The effects of experimental varicocele on testicular histology and fertility in monorchic adult rats

Varicocele-caused progressive damage in bilateral testis and sertoli cell-only syndrome in homolateral testis in rats

Background

We aimed to investigate whether varicocele (VC) in rats can cause Sertoli cell-only syndrome (SCOS).

Material/Methods

Forty adolescent SD rats were randomly divided into 4 groups: 4-weeks control group, 4-weeks experimental group, 12-weeks control group, and 12-weeks experimental group. Left varicocele models were introduced by partially ligating left kidney veins for the experimental groups, and the sham surgery groups as controls were executed with exactly the same surgery as in the experimental groups except for the ligation. Rats in control and experimental groups for 4 and 12 weeks were killed after laparotomy at 4 and 12 weeks, respectively, the testes were taken out and fixed in fixative containing 4% polyformaldehyde, then were stained by hematoxylin and eosin (HE). The density and viability of sperm were analyzed by computer-aided sperm analysis.

Results

Compared with rats in 4-weeks and 12-weeks control group, histological structures of bilateral testes in both experimental groups were impaired, most of them showing as focal focuses. The pathological changes of testes in rats of the 12-weeks experimental group were bilateral, and included atrophy of seminiferous tubules, turbulence of spermatogenic cells in seminiferous tubules, defluvium of most spermatogenic cells, abortion of spermatogenesis, and degradation of spermatogenic epithelia. One rat in the 12-weeks experimental group was shown having SCOS, with the spermatogenic cells in seminiferous tubules completely flaked, degraded, or absent, and only Sertoli cells lined the seminiferous tubules.

Conclusions

Laboratory VC caused progressive impairment of homolateral testes, and SCOS could be induced when the damage was severe. Our results indicate that asthenozoospermia, azoospermia, and SCOS can be prevented by the earlier treatment of VC.

Role of varicocele repair for male infertility in the era of assisted reproductive technologies

Varicocele is an abnormal condition characterized by dilatation of the pampiniform plexus veins draining the testis and is present in 15 % of men. Varicoceles have an adverse effect on spermatogenesis and are the most common cause of male infertility. Approximately 35 % of infertile men and more than 70 % of men with secondary infertility were reported to have varicoceles. Although data on methods of varicocele repair are accumulating, there remains controversy regarding the indications and techniques for varicocele repair. In addition, the role of varicocele repair in this era of assisted reproductive technologies continues to be debated. In this study, we performed a comprehensive PubMed search in order to review the current status of varicocele repair for male infertility. We reviewed English-language studies published from 1992 through 2013. After reviewing the articles, we identified a recent meta-analysis of four randomized controlled trials, which found that varicocele repair for oligozoospermic men was associated with better pregnancy rates as compared with observation. Our review of prospective studies showed that all semen parameters, including sperm concentration, motility, and progressive motility, were significantly improved after varicocele repair. We also summarize the findings of recent studies reporting beneficial effects of varicocele repair, i.e., decreased oxidative stress and sperm DNA fragmentation after varicocele repair and superior cost effectiveness versus in vitro fertilization/intracytoplasmic sperm injection alone, which may be important in the era of assisted reproductive technologies. Varicocele repair is a widespread, well-established procedure that can improve semen parameters in men with infertility. The effect of such treatment on the pregnancy rate is unclear because evidence is limited due to difficulties in recruiting patients for studies. Among the repair techniques, microsurgical repair using a subinguinal approach is potentially the best practice, although this procedure requires training in microsurgery. All these topics require further research in studies with sufficient patient enrollment and follow-up.

The effect of the partial obstruction site of the renal vein on testis and kidney in rats: is the traditional animal model suitable for varicocele research?

PURPOSE

We investigated the influence of the location of the partial renal vein obstruction on the left kidney, the bilateral testes, and cauda epididymal sperm quality and determined whether this animal model is suitable for varicocele study.

MATERIALS AND METHODS

A total of 25 adult male Sprague-Dawley rats were assigned to three groups: group 1 (experimental varicocele by partial ligation medial to the internal spermatic vein for 8 weeks, n=8), group 2 (partial ligation lateral to the internal spermatic vein for 8 weeks, n=10), and group 3 (sham operation for 8 weeks, n=7). Rats in groups 1, 2, and 3 underwent a left nephrectomy and bilateral orchiectomy at 8 weeks after the operation. Histological changes and Johnsen score in both testes were analyzed. Fibrotic changes in the left kidney were assessed by quantitative image analysis. Numbers of sperm and proportions of motile sperm in the cauda epididymides were determined.

RESULTS

Significant histological abnormalities and Johnsen score changes were observed in the testes in group 1. Renal fibrosis did not differ significantly among the groups. The proportions of motile sperm were significantly lower bilaterally in group 1 than in groups 2 and 3. However, the mean bilateral epididymal sperm count in group 1 was not significantly lower than in groups 2 and 3.

CONCLUSIONS

Our results showed that experimental varicocele in the rat, induced by partial ligation medial to the internal spermatic vein, influences epididymal sperm quality without harmful effects on the left kidney. The present study certifies that this traditional animal model is suitable for varicocele research.

Somatic angiotensin converting enzyme in varicocele

The ACE is found as two isozymes in the body. A somatic isozyme found in blood and several other tissues, and a testis-specific isozyme found only in developing spermatids and mature sperm. In this study, we investigated the ACE activity in left spermatic vein blood samples of infertile patients with varicocele and its correlation to spermatologic parameters. The somatic ACE activities were determined in the peripheral and left spermatic vein blood samples from 31 infertile patients who underwent variococelectomy, and 11 fertile control subjects underwent left inguinal herniorraphy. The somatic ACE activity was measured by kinetic spectrophotometric assay. Semen analyses were performed according to WHO guidelines. The mean somatic ACE activities of peripheral and left spermatic veins of the varicocele group were 60.3 +/- 23.0 and 60.2 +/- 23.2 U/L, respectively. In control group, peripheral and left spermatic vein ACE activities were found as 56.8 +/- 17.1 and 56.5 +/- 15.5 U/L, respectively. There was no significant difference between the ACE activity in peripheral and left spermatic vein blood sample from the varicocele and control group. There was no statistically significant correlation between the spermatologic parameters and ACE activities in the spermatic and peripheral vein in both of varicocele and control groups. As a result, it may be suggested that the somatic ACE has no causative role in pathophysiology of varicocele and varicocele related infertility.

Testicular oxidative stress. Effects of experimental varicocele in adolescent rats

OBJECTIVE

This present study was undertaken to determine the levels of malondialdehyde (MDA), nitric oxide (NO) and total antioxidant status (TAS) in testes of adolescent rats with experimental bilateral varicocele and to determine the effects of oxidative stress on testis produced by varicocele.

METHODS

6-week-old, male Wistar rats, weighing 146-334 g (228.37 +/- 41.34 g), were randomly allocated into two groups. The first group underwent selective and bilateral partial ligation of the spermatic vein (n = 28), and the second group underwent a sham operation and served as the controls (n = 15). Animals were sacrificed 12 weeks after surgery and dilatation of the spermatic veins was observed in the first study group. Bilateral orchiectomy was performed in all rats, and MDA, NO and TAS levels were measured.

RESULTS

In the study group, the mean MDA (SEM) level was 15.58 +/- 6.07 micromol/g protein, and in the control group, it was 11.59 +/- 3.86 micromol/g protein, respectively; this difference was statistically significant (p < 0.05). The mean NO level was 82.73 +/- 77.84 nmol/g protein in the study group, whereas 28.65 +/- 20.18 nmol/g protein in the control group, this difference was also statistically significant (p < 0.005). The mean TAS levels of the study and control groups were 0.91 +/- 0.32 and 1.78 +/- 0.46 nmol/g tissue, respectively, and this difference was also statistically significant (p < 0.001). But there was no correlation between these three parameters (MDA<-->TAS: r = -0.103, p > 0.05; MDA<-->NO: r = -0.104, p > 0.05; NO<-->TAS: r = -0.123, p > 0.05).

CONCLUSION

These findings suggest that varicocele may change the testicular oxidative status and may play a role in testicular dysfunction that causes infertility.