Abstract: As there is increasing evidence that benign prostatic hyperplasia and its related acute urinary retention (AUR) induce over active bladder (OAB) syndrome, we investigated the effects of AUR on bladder function over a 4-week period in a rat model. Ten-week-old female Sprague-Dawley rats were used in this study. AUR was induced by clamping the distal urethra of each rat with a small clip, and then infusing 3 ml (0.6 ml/min) of saline with an infusion pump through a transurethral catheter (22G). The obstruction was sustained for 60 min and the clip was removed and then the bladder was allowed to drain through the catheter. The bladder function was estimated by voiding behavior studies (at 3 days, 1, 2, 3, and 4 weeks), cystometric studies (at 2 and 4 weeks) and organ bath studies using KCl and carbachol (at 2 and 4 weeks). Furthermore, we evaluated histological changes in the rat bladder 2 and 4 weeks after the induction of AUR. The same parameters were also measured in non-AUR rats (control group). The rat bladder weight in the AUR group at 2 weeks was significantly larger than that of the controls, and returned to the control level 4 weeks after the AUR episode. The voiding behavior studies showed significant increase in micturition frequency per day and decrease in single voiding volume 3 days after the induction of AUR, and this voiding behavior was continued for more than 2 weeks. The cystometric studies showed a significant decrease in single-voided volume at 2 weeks rat. However, no significant changes of the other parameters were observed in the rats. The histological studies showed significant infiltration of neutrophils and lymphocytes, as well as increase in turnover of epithelium in AUR rats at 2 weeks, while significant increases in fibrosis in submucosal layer were observed in AUR rats at 4 weeks. This study demonstrated that bladder dysfunction in the rat model caused by AUR needs more than 2 weeks of recovery period. The AUR-associated alterations in the bladder may represent a key clue to understand the underlying pathophysiological mechanisms, which take place in OAB syndrome.
Abstract: As there are increasing evidences that human diabetes induces cardiovascular dysfunction, we investigated the type-2 diabetes-induced endothelial dysfunction in the early and late-stage Goto-Kakizaki (GK) rat aorta. We performed organ bath studies, and examined the changes in expression levels of muscarinic M(3) receptor, endothelial, inducible, and neuronal nitric oxide synthase (eNOS, iNOS, and nNOS, respectively) mRNAs in the rat aorta utilizing real-time polymerase chain reaction in 12-week-old and 70-week-old GK rats as well as in age-matched Wistar rats. In the 12-week-old GK rat aorta, a significant increase in norepinephrine-induced contraction and a significant decrease in acetylcholine-induced relaxation as well as significant increases in expression levels of muscarinic M(3) receptor and eNOS and a significant decrease in nNOS mRNAs were observed compared to age-matched controls. In the older GK rat aorta, significant decreases in acetylcholine- and nitroglycerine-induced relaxations as well as significant decreases in the expression levels of muscarinic M(3) receptor, eNOS, iNOS, and nNOS mRNAs were observed compared to those in the younger GK rats. In contrast, although significant decreases in acetylcholine and nitroglycerine-induced relaxations were observed, the expression levels of muscarinic M(3) receptor, eNOS, iNOS, and nNOS mRNAs in the older Wistar rats aorta were unchanged, increased, increased and decreased, respectively, compared to the younger Wistar rat aorta. These results indicate that endothelial dysfunction in the rat aorta progresses with age and development of diabetes condition, and that decreased relaxations in the late-stage rat aorta may be due to these alterations.
Abstract: OBJECTIVE To investigate the effect of edaravone, a radical scavenger, on ischaemia-reperfusion (I-R) injury in the testes. MATERIALS AND METHODS Eight-week-old male Sprague-Dawley rats were allocated to one of four groups: a no-drug group subjected to induction of 30-min of ischaemia and 60-min reperfusion; two drug groups administered edaravone at 1 or 10 mg/kg intraperitoneal and then subjected to 30-min ischaemia and 60-min reperfusion; and a sham-operated control group administered edaravone at 10 mg/kg intraperitoneal. To induce testicular I-R, the right testis was exposed outside of the body and the testicular artery was clamped with a small clip for 30 min. Blood flow and nitric oxide (NO) release were monitored in real time simultaneously with a laser Doppler flowmeter and an NO-selective electrode, respectively. After death the tissue levels of NO(2)-NO(3) (a marker of NO production), malondialdehyde (a marker of lipid peroxidation), 8-hydroxydeoxyguanosine (a marker of oxidative DNA damage), myeloperoxidase (a marker of neutrophil infiltration), and heat-shock protein 70 (HSP 70) and its mRNA were measured. The testicular tissue was also analysed histologically. RESULTS Clamping the testicular artery resulted in a decrease of blood flow to 0-5% of the basal level measured before clamping. NO release was increased during clamping and gradually recovered to the basal level on removing the clip. Interestingly, the peak of NO release in rats of the no-drug group occurred at the start of reperfusion, while that in the high-dose drug group occurred several minutes later. The levels of NO(2)-NO(3), malondialdehyde, 8-hydroxydeoxyguanosine, myeloperoxidase and HSP 70 and its mRNA, and histological variables, were significantly greater in the no-drug I-R group than in the control, and these variables were ameliorated by treatment with edaravone. CONCLUSION These results indicate that edaravone reduces the oxidative stress and prevents the testicular damage induced by I-R.
Abstract: We evaluated the development of embryos generated from the fertilisation of oocytes with spermatozoa isolated from animals with primary testicular damage (PTD). Embryos derived in vivo or in vitro from oocytes fertilised with spermatozoa produced by PTD rats that had undergone surgical treatment for the PTD (group A1), or PTD rats (group A2), or control rats (group B) were cultured and transferred to recipients. At the end of the experimental period, the fertilisation potential of each rat was assessed in vitro (IVF trials). Sperm 8-oxodG/dG ratio (a marker of DNA oxidative status) was significantly larger in group A2 than in groups A1 and B. Blastocysts of the group A2 transferred to recipients demonstrated a significantly larger loss before implantation than transferred blastocysts of groups A1 or B. In addition, the proportion of implanted blastocysts that could not complete the intrauterine development was significantly larger in group A2 than in groups A1 and B. This study reveals a post-fertilisation detrimental effect in animals with PTD on the capacity of oocytes (fertilised either in vitro or in vivo) to develop in vitro and implant after transferring them to recipients probably attributable to sperm DNA oxidative damage.
Abstract: This review study refers to the possibility to employ PDE5 inhibitors as an adjunct tool for the therapeutic management of male infertility. The literature tends to suggest that PDE5 inhibitors enhance the Leydig cell secretory function and play a role in the regulation of the contractility of the tunica albuginea and the epididymis. In addition, the literature suggests that PDE5 inhibitors increase the prostatic secretory function that results in an improvement in sperm motility in several cases. Some studies additionally demonstrate a role of PDE5 inhibitors in the regulation of sperm capacitation process. Additional placebo-controlled, randomized, blind studies are necessary to unequivocally suggest a therapeutic role of PDE5 inhibitors in the alleviation of semen disorders and male infertility.
Abstract: We evaluated the potential for growth and intrauterine development of embryos generated from the fertilization of oocytes with spermatozoa recovered from animals with chronic renal failure (CRF). Group A included sham-operated rats (n = 28), group B1 involved CRF rats that had undergone erythropoietin plus bromocryptine treatment (n = 28), and group B2 included CRF rats that had received normal saline. Embryos derived from the in vitro fertilization of oocytes with spermatozoa recovered from rats of group A or group B1 or group B2 were transferred to female recipients. We induced CRF in a group of rats (group B; n = 56; the total kidney volume was reduced to one-sixth with two operations). One week after the second operation, the rats of group B were randomly divided into group B1 (they subsequently received bromocryptine plus erythropoietin) and group B2 (they received injections of saline). Nine weeks after the second operation, the fertility of each male rat was assessed by mating tests and in vitro fertilization of oocytes. The mean litter size was significantly smaller in the subpopulation of fertile animals in group B2 than in the fertile rats of group B1 and in the fertile rats of group B1 than in the fertile rats of group A. Per cent of transferred blastocysts that developed into alive offspring were significantly lower in group B2 than in group B1 and in group B1 than in group A. Epididymal spermatozoa demonstrated a significantly larger DNA-oxidative damage in group B2 than in group B1 and in group B1 than in group A. These findings demonstrate that sperm-DNA damage because of CRF development is accompanied by a defect in the development of embryos generated in vitro. We may suggest that bromocryptine and erythropoietin protecting sperm DNA from oxidative damage improve reproductive potential in rats with CRF.
Abstract: The aim of this review study is to elucidate the effects that phosphodiesterase 5 (PDE5) inhibitors exert on spermatozoa motility, capacitation process and on their ability to fertilize the oocyte. Second messenger systems such as the cAMP/adenylate cyclase (AC) system and the cGMP/guanylate cyclase (GC) system appear to regulate sperm functions. Increased levels of intracytosolic cAMP result in an enhancement of sperm motility and viability. The stimulation of GC by low doses of nitric oxide (NO) leads to an improvement or maintenance of sperm motility, whereas higher concentrations have an adverse effect on sperm parameters. Several in vivo and in vitro studies have been carried out in order to examine whether PDE5 inhibitors affect positively or negatively sperm parameters and sperm fertilizing capacity. The results of these studies are controversial. Some of these studies demonstrate no significant effects of PDE5 inhibitors on the motility, viability, and morphology of spermatozoa collected from men that have been treated with PDE5 inhibitors. On the other hand, several studies demonstrate a positive effect of PDE5 inhibitors on sperm motility both in vivo and in vitro. In vitro studies of sildenafil citrate demonstrate a stimulatory effect on sperm motility with an increase in intracellular cAMP suggesting an inhibitory action of sildenafil citrate on a PDE isoform other than the PDE5. On the other hand, tadalafil's actions appear to be associated with the inhibitory effect of this compound on PDE11. In vivo studies in men treated with vardenafil in a daily basis demonstrated a significantly larger total number of spermatozoa per ejaculate, quantitative sperm motility, and qualitative sperm motility; it has been suggested that vardenafil administration enhances the secretory function of the prostate and subsequently increases the qualitative and quantitative motility of spermatozoa. The effect that PDE5 inhibitors exert on sperm parameters may lead to the improvement of the outcome of assisted reproductive technology (ART) programs. In the future PDE5 inhibitors might serve as adjunct therapeutical agents for the alleviation of male infertility.
Abstract: Pregnancies achieved by assisted reproduction technologies, particularly by intracytoplasmic sperm injection (ICSI) procedures, are susceptible to genetic risks inherent to the male population treated with ICSI and additional risks inherent to this innovative procedure. The documented, as well as the theoretical, risks are discussed in the present review study. These risks mainly represent that consequences of the genetic abnormalities underlying male subfertility (or infertility) and might become stimulators for the development of novel approaches and applications in the treatment of infertility. In addition, risks with a polygenic background appearing at birth as congenital anomalies and other theoretical or stochastic risks are discussed. Recent data suggest that assisted reproductive technology might also affect epigenetic characteristics of the male gamete, the female gamete, or might have an impact on early embryogenesis. It might be also associated with an increased risk for genomic imprinting abnormalities.
Abstract: Induction of meiotic and post-meiotic alterations of male germ cells in vitro has been the target of several research efforts since 1960. However, to date, the establishment of an ideal culture system in which spermatogonial stem cells can be maintained and directed to proliferate and undergo meiosis and complete spermiogenesis does not exist. This is attributed to the difficulties concerning the isolation and purification of defined subpopulations of germ cells and the establishment of male germ cell lines. In addition, there is no adequate knowledge regarding the optimal biochemical conditions that promote the survival and differentiation of germ cells in long-term cultures. This review focuses on the methodologies that have been proved sufficient to achieve differentiation of cultured male germ cells. Furthermore, the factors regulating spermatogenesis and the technical prerequisites to achieve differentiation of cultured male germ cells are described. Finally, the role of in vitro cultures of immature diploid germ cells in the therapeutic management of men negative for haploid cells in their testes and the subsequent potential genetic and epigenetic risks are discussed.
