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

Abstract

To determine the effects of a left-sided experimental varicocele on testicular morphology and fertility in right hemicastrated adult rats. A double-controlled experimental study was carried out using mature Sprague-Dawley rats, with 12 rats in each treated group and five corresponding controls. Group 1 underwent right orchidectomy, group 2 right orchidectomy and a left varicocele, and group 3 only a left varicocele; each control group underwent a corresponding sham operation. Two months after surgery each rat was placed with two mature female rats for one month to assess fertility. All the rats were then killed and their testes weighed; the mean testicular weight was calculated for each group and the mean seminiferous tubule diameter (STD) measured. Johnsen scores and histological abnormalities were evaluated for each testis using light microscopy. The mean (SEM) testicular weight and STD in group 2 were significantly lower, at 1311 (100) mg and 225 (11) microm, respectively, than in group 1, at 1771 (28) mg and 255 (4) microm (P<0.05). The mean weights of both testes in rats in group 3 were significantly lower than those in group 1 (P<0.05) and although both mean STDs were less than in group 1, the differences were not significant (P>0.05). There were no differences between the Johnsen scores in groups 2 and 3. There were severe histological abnormalities in the left testes in three of nine and two of eight animals in group 2 and 3, respectively; in group 3, changes in the right testis were detected in one rat. Six of nine and seven of eight rats were fertile in group 2 and 3, respectively. Experimental left varicocele decreased the left testicular weight and STD in both hemicastrated and intact adult rats. However, the presence of the right testis is important for preserving fertility.