Effects of Varicocele on Electrical Field Stimulation-Induced Biphasic Twitch Responses in the Ipsilateral and Contralateral Rat Vasa Deferentia

Abstract

Aim: Although little is known about the mechanisms, varicocele is considered as one of the factors leading to male infertility. Since reduced motility of the vas deferens was shown to contribute to male infertility, in this study we aimed to investigate the effect of varicocele on electrical field stimulation (EFS)-induced biphasic contractions of the vas deferens in order to evaluate the effect of varicocele on the motility of the vas deferens. Material and Methods: A total of 26 Sprague-Dawley rats (200–250 g) were assigned randomly into two groups: sham (n = 10) and varicocele (n = 16). Varicocele was produced by partial obstruction of the left renal vein. Four weeks after the surgical procedure, vasa deferentia were harvested and EFS-induced responses were recorded from the strips prepared from ipsilateral and contralateral sides via Grass isometric force displacement transducers. Exogenous α-β methyl ATP was applied at the concentration of 10^–5M to the vasa deferentia strips, and exogenous noradrenalin was applied cumulatively at the concentrations between 10^–7 and 10^–4M. At the end of each experiment, 80 mM KCl was applied to induce contractions. All contractions were expressed as the percentage of the 80 mM KCl-induced contractions. Results: Varicocele significantly inhibited both phases of EFS-induced biphasic contractions in the ipsilateral side, whereas in the contralateral site it did not produce any change. However, there was no change in exogenously applied α-β methyl ATP, noradrenalin and KCl-evoked contractions of the vasa deferentia obtained from both sides. Conclusions: These results suggest that varicocele affects the ipsilateral vas deferens motility by reducing neurotransmitter release.

Varicocele repair: does it still have a role in infertility treatment?

“…Although vas deferens motility was not traditionally thought to be associated with varicocele, Ozen et al [28] have documented a novel effect of varicocele on vas deferens motility, at least in a rat model. In a recent study, they demonstrated decreased contractile response in the ipsilateral vas deferens compared with the contralateral vas in rats with induced varicoceles.…”

“…In 2005, Nicotina et al [27] showed increased expression of aquaporin receptor-1 (AQP-1) on venular endothelial cell membranes and in the cell membrane of Sertoli cells, diploid germ cells, and haploid cells in patients with varicocele. This may suggest that in the setting of varicocele, the testis is attempting to overcome fluid imbalance in the tubular and interstitial compartments.Although vas deferens motility was not traditionally thought to be associated with varicocele, Ozen et al [28] have documented a novel effect of varicocele on vas deferens motility, at least in a rat model. In a recent study, they demonstrated decreased contractile response in the ipsilateral vas deferens compared with the contralateral vas in rats with induced varicoceles.…”

The effects of varicocele and its surgical correction on vas deferens motility

“…In an earlier study, Ozen et al [8] found that the varicocele significantly inhibited the ''either'' phases of EFS induced biphasic contractions in the ipsilateral side. Their study suggested that the varicocele has caused damages in the presynaptic area and affected vas deferens motility.…”

“…There is limited data in the literature investigating the effects of varicocele on the vas deferens motility [8]. The aim of this study is to evaluate not only the motility defects of vas deferens for the period of varicocele, but also the effects of surgical varicocele correction on the vas deferens motility.…”

Physiological and pharmacological aspects of the vas deferens—an update

“…In conjuction with this study, Gur et al (2010) also demonstrated that rats co-treated with sildenafil and L-NAME reversed this EFS and α−β-methylATP hypercontractile property of the vas deferens. Additionally, a varicocele model has resulted in a decrease vas contractile response (Ozen et al, 2007). Taken together, alterations in vas are clinically applicable, and may have implications for fertility, ejaculation abnormalities, and possibly vasectomy associated pain (Granitsiotis and Kirk, 2004; Tandon and Sabanegh, 2008).…”