A comparison of the effects of N-acetylcysteine and ethyl pyruvate on experimental testicular ischemia-reperfusion injury

Pathophysiology and management of testicular ischemia/reperfusion injury: Lessons from animal models

Testicular torsion is a urological emergency that involves the twisting of the spermatic cord along its course. Compelling pieces of evidence have implicated oxidative stress-sensitive signaling in pathogenesis of testicular I/R injury. Although, surgical detorsion is the mainstay management; blockade of the pathways involved in the pathogenesis may improve the surgical outcome. Experimental studies using various testicular I/R models have been reported in a bid to explore the mechanisms associated with testicular I/R and evaluate the benefits of potential therapeutic measures; however, most are limited by their shortcomings. Thus, this review was intended to describe the details of the available testicular I/R models as well as their merits and drawbacks, the pathophysiological basis and consequences of testicular I/R, and the pharmacological agents that have being proposed to confer testicular benefits against testicular I/R. This provides an understanding of the pathophysiological events and available models used in studying testicular I/R. In addition, this research provides evidence-based molecules with therapeutic potentials as well as their mechanisms of action in testicular I/R.

Protective effect of ligustrazine on oxidative stress and apoptosis following testicular torsion in rats

Testicular torsion is a common urologic emergency and one of the causes of infertility in males. It has been reported that ligustrazine may decrease oxidative stress and reduce ischemia-reperfusion injury. This study aims to investigate the protective effect of ligustrazine in ischemia-reperfusion injury after testicular torsion-detorsion. First, 40 rats were randomly and equally divided into TMP (Ligustrazine) group, the Testicular torsion (T/D) group, the Sham (Sham operation) group, and Control group. The left testis of rats in the TMP and T/D group was rotated for 2 h. The TMP group was intraperitoneally injected with ligustrazine solution and the T/D and the Sham groups were injected with normal saline. The left testes of four groups were obtained for assay on the 4th day after the operation. Average level of superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) were higher in Sham and Control groups than T/D group and TMP group. Conversely, average level of malondialdehyde (MDA) and reactive oxygen species (ROS) was lower in Sham and Control groups than T/D group and TMP group. In contrast with the T/D group, SOD, GPX, and CAT enzymatic activities increased, whereas MDA and ROS content decreased in the TMP group (P < 0.05). Microscopic observation showed that the testicular tissue of the Sham and Control groups were basically normal. The TMP and T/D groups had significant testicular tissue damage, whereas the TMP group had less damage and apoptosis than the T/D group. The apoptotic index of germ cells in the TMP group (13.05 ± 4.41) was lower than the T/D group (30.23 ± 11.31) (P < 0.05) and higher (P < 0.05) than the Sham group (0.56 ± 0.29). So we found that Ligustrazine lowered ischemia-reperfusion injury after testicular torsion-detorsion by decreasing the reactive oxygen species and suppressing apoptosis.

Potential therapeutic effects of ethyl pyruvate in an experimental rat appendicitis model

BACKGROUND

Pathophysiology of appendicitis is associated with the underlying inflammatory processes. Ethyl pyruvate (EP) has potent antioxidant and anti inflammatory properties. In this study, we aimed to investigate the effects of EP on the treatment of appendicitis and to examine whether adding EP to the antibiotic treatment could increases the effectiveness of the treatment in a rat appendicitis model.

METHOD

Thirty two Wistar rats, which had previously created appendicitis, were randomly divided into 4 groups: Group 1 (0.1 ml saline solution), Group 2 (15 mg/kg ceftriaxone), Group 3 (50 mg/kg EP), Group 4 (EP 50 mg/kg + ceftriaxone 15 mg/kg). In all groups, saline solution, ceftriaxone and EP were administered intraperitoneally and the same procedure was repeated twice a day for the following five days. On day 6, the rats underwent relaparotomy and then intraabdominal findings were recorded. Histopathological examination and interleukin 6 (IL 6) level were performed on appendiceal specimens.

RESULTS

Intra abdominal adhesion score was significantly lower in Group 4 than in Group 1. Total inflammation score was significantly lower in Group 2 than in Group 1 and was significantly lower in Group 4 than in Group 3 and 1. IL 6 level was significantly lower in Group 4 than in Group 3 and 1.

CONCLUSION

We found that adding EP to the antibiotic therapy increased the efficacy of the treatment in the rat appendicitis model. Further studies are required to apply our findings to the clinical setting.

Ethyl pyruvate: A newly discovered compound against ischemia-reperfusion injury in multiple organs

Ischemia-reperfusion injury (IRI) is a process whereby an initial ischemia injury and subsequent recovery of blood flow, which leads to the propagation of an innate immune response and the changes of structural and functional of multiple organs. Therefore, IRI is considered to be a great challenge in clinical treatment such as organ transplantation or coronary angioplasty. In recent years, ethyl pyruvate (EP), a derivative of pyruvate, has received great attention because of its stability and low toxicity. Previous studies have proved that EP has various pharmacological activities, including anti-inflammation, anti-oxidative stress, anti-apoptosis, and anti-fibrosis. Compelling evidence has indicated EP plays a beneficial role in a variety of acute injury models, such as brain IRI, myocardial IRI, renal IRI, and hepatic IRI. Moreover, EP can not only effectively inhibit multiple IRI-induced pathological processes, but also improve the structural and functional lesion of tissues and organs. In this study, we review the recent progress in the research on EP and discuss their implications for a better understanding of multiple organ IRI, and the prospects of targeting the EP for therapeutic intervention.

Sinapic acid reduces ischemia/reperfusion injury due to testicular torsion/detorsion in rats

This study aimed to investigate the protective effect of sinapic acid (SA) on biochemical and histopathological changes in an experimental testicular torsion-detorsion rat model. Twenty-four rats were randomised into four groups: sham group, ischemia/reperfusion (IR) group subjected to testicular torsion for 2 hr and then detorsion for 4 hr, and two groups treated with SA1 and SA2 (10 mg/kg and 20 mg/kg, by single intraperitoneal injection, 30 min before reperfusion). Serum testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured by an autoanalyzer, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), protein carbonyl (PC), and nitric oxide (NO) oxidative stress parameters by spectrophotometric methods, and tumour necrosis factor (TNF-α), interleukin-1 beta (IL-1β), and interleukin 6 (IL-6) parameters by the Elisa method. In addition, immunohistochemical and histopathological examinations were performed on testicular tissues. There was no significant difference between the groups in terms of serum testosterone, FSH and LH levels (p > .05). SA significantly reduced increased testicular damage, oxidative stress, inflammation, cell death and also restored decreased antioxidant enzyme activities (p < .05). Pre-treatment of rats with SA reduced testicular dysfunction and morphological changes IRI. SA's antioxidant, anti-inflammatory, and antiapoptotic properties were found to be protective against testicular IR.

Testicular Torsion and Spermatogenesis

Testicular torsion (TT) is a common urologic emergency that can occur at any age. It is most common in newborns and during puberty. Prompt evaluation and management is required to salvage the testis following an episode of torsion. TT brings about damage to testicular tissue and spermatogenesis through various hypothesized mechanisms; however there is a consensus that the effects of ischemia, ischemia-reperfusion injury, and oxidative stress account for the most destructive effects. Numerous studies have examined the effects of various agents and therapies in limiting the effects of TT on the testis.

Potential therapeutic effects of ethyl pyruvate and N-acetyl cysteine in an experimental rat model of corrosive esophageal

BACKGROUND AND STUDY AIMS

Esophageal burns due to ingestion of corrosive substances are frequently seen in both children and adults. However, there is no standard method of treatment to prevent associated mortality and morbidity. Therefore, this study aimed to evaluate the effects of known antioxidants, namely N-acetyl cysteine and ethyl pyruvate, on esophageal damage due to sodium hydroxide-induced corrosive burns.

MATERIALS AND METHODS

Thirty-five female rats were randomly assigned to five equal groups. Group 1 was the sham group, while Group 2 was the control group. Group 3 received N-acetyl cysteine, Group 4 received ethyl pyruvate, and Group 5 received both N-acetyl cysteine and ethyl pyruvate. Rats in the "burn" groups were gavage-fed with 0.2mL of 25% NaOH. All esophagi were extracted on day 4 for histopathological evaluation.

RESULTS

Total histopathological damage scores were evaluated at the end of the study. Groups 3 and 5 were significantly different from the control group in terms of total histopathological scores (p = 0.001), while no significant difference was seen with Group 4. Stenosis index results in groups 3 and 5 were similar to those seen with total histopathological scores (p = 0.004).

CONCLUSION

N-acetyl cysteine, alone or in combination with ethyl pyruvate, may be useful in the treatment of esophageal damage associated with corrosive substances and in achieving histopathological improvement in an experimental setting.

Antioxidant effects of N-acetylcysteine on the male reproductive system: A systematic review

This study aimed to evaluate the effect of N-acetyl cysteine on the male reproductive system and consensus and classification of data found from previous studies. It is undeniable that N-acetyl cysteine as a powerful antioxidant compound can medicate many diseases such as cardiovascular, kidney, liver and reproductive system disorders. With the increasing environmental pollution that has a direct adverse effect on male fertility, the use of this compound is able to positively function on human fertility health. In this study, we have been collected the main data of scientific articles (1994-2020) about N-acetyl cysteine effects. By searching in the scientific databases of PubMed, Google Scholar, Science Direct, Wiley and Web of Science, related articles were extracted. As a result, all observations have confirmed that N-acetyl cysteine can improve and normalise the spermatogenesis in the male reproduction system.

The long term effects of intrascrotal low dose and high dose N-acetylcysteine on testis damage in rat model of testicular torsion

BACKGROUND/PURPOSE

During testicular torsion, the testes face oxidative damage owing to ischemia/reperfusion. We studied the long term effects of the intrascrotal administration of N-acetylcysteine (NAC) during detorsion procedure in a rat model of testicular torsion.

METHODS

Twenty-eight rats were divided into 4 groups: (1) Control group: No procedure was done (2): Torsion-detorsion group: Testis torsion applied for 3 h (3): Low Dose Group: After testis torsion-detorsion (for 3 h) 10 mg/kg NAC was given into tunica vaginalis (4): High Dose Group: After testis torsion-detorsion (for 3 h) 100 mg/kg NAC was given into tunica vaginalis. We measured dimensions of the testes and examined pathological findings and Johnsen and Cosantino Scores.

RESULTS

For testes height and volume, high dose NAC group had better results than the torsion-detorsion group (p = 0.019, p = 0.049). Testes weight showed no difference (p = 0.204). Sertoli cell number per tubule in the high dose NAC group was statistically different than the torsion-detorsion group (p = 0.017).

CONCLUSIONS

When NAC was given intrascrotally at a dose of 100 mg/kg, it decreased the loss of testis volume and height, and Sertoli cell number per tubule was similar to the control group. These results suggest that the higher dose intrascrotal NAC administered during detorsion may have a protective effect.

The air-liquid interface culture of the mechanically isolated seminiferous tubules embedded in agarose or alginate improves in vitro spermatogenesis at the expense of attenuating their integrity

Optimization of tissue culture systems able to complete male germ cell maturation to post-meiotic stages is considered as an important matter in reproductive biology. Considering that hypoxia is one of the factors limiting the efficiency of organ culture, the aim of this study was to use isolated seminiferous tubules (STs), having more surface and less thickness, in an organotypic culture system in order to improve oxygen diffusion and reduce hypoxia. The mechanically separated STs embedded in agarose or alginate and 1-3-mm³ testicular tissue fragments of 3 adult mice were separately placed on the flat surface of agarose gel that was half-soaked in the medium. Survival and differentiation of germ cells using PLZF and SCP3 markers, identity of Sertoli cell using GATA4, cell proliferation with the Ki67 marker, and ST integrity using a ST scoring were evaluated up to 36 d at different culture times, each corresponding to the duration of one spermatogenic cycle. We observed a significantly reduced ST integrity in STs embedded in agarose or alginate on day 9 (versus tissue fragments p ≤ 0.05). There was no difference in the number of PLZF-positive cells between groups, but the number of SCP3 (in all-time points) and GATA4-positive cells was significantly higher in the culture of embedded STs. Although embedding STs can be useful for the progress of in vitro spermatogenesis, it makes them sensitive to degeneration. Further improvements are required to modify the air-liquid interface method to maintain ST integrity.

Effect of ethyl pyruvate on oxidative state and endoplasmic reticulum stress in a rat model of testicular torsion

We investigated the effects of ethyl pyruvate (EP) on oxidative and endoplasmic reticulum (ER) stress due to experimental testicular ischemia-reperfusion (I-R). Eighteen rats were divided into a control group, a torsion-detorsion (T-D) group and an EP group. For pretreatment of the EP group, 50 mg/kg EP was given intraperitoneally (i.p.) 30 min before detorsion. Tissue 4-hydroxynonenal (4-HNE) and 78-kDa glucose-regulated protein (GRP78) levels were determined using enzyme-linked immunosorbent assay (ELISA) kits. Tissue total oxidant status (TOS) and total antioxidant status were determined using colorimetric methods. Histology of the tissues was evaluated using hematoxylin and eosin staining. In the T-D group, tissue 4-HNE, GRP78, TOS and oxidative stress index levels were significantly higher than for the control group. The increases were reduced significantly by EP pretreatment. Our findings suggest that EP can inhibit I-R induced testicular injury by suppressing oxidative and ER stress. EP may be a useful adjunctive treatment for surgical repair in humans.

Mesenchymal stem cells restore the sperm motility from testicular torsion-detorsion injury by regulation of glucose metabolism in sperm

Background

Testicular torsion is an urological emergency that may lead to infertility due to ischemic injury. Promptly surgical correction by orchiopexy is the only way to avoid infertility and no effective treatment for restoration of spermatogenesis. We previously reported that mesenchymal stem cells (MSCs), through local injection upon testicular torsion-detorsion, restored the spermatogenesis without differentiation into sperm. In this study, molecular mechanisms of MSCs in regulating germ cell activity induced by testicular torsion-detorsion were investigated.

Methods

Sixteen male Sprague-Dawley rats 6–8 weeks old received left testis 720° torsion for 3 h followed by detorsion with or without MSCs. Right inguinal skin incision without testicular torsion served as control. MSCs with 3 × 10⁴ cells were locally injected into left testis 30 min before detorsion. Three days after the surgery, orchiectomy was executed and the testis, epididymis, and sperm were separated to each other. Functional assessments on sperm included counting sperm amount and sperm motility, staining F-actin, and quantifying adenosine triphosphate (ATP) content. The hallmarks of glycogenesis and glycolysis in each tissue segment were measured by Western blot.

Results

Testicular torsion-detorsion significantly decreased the amount of sperm, inhibited the motility, declined the F-actin expression, and reduced the content of ATP in sperm. Local injection of MSCs improved sperm function, particularly in sperm motility. With MSCs, ATP content and F-actin were preserved after testicular torsion-detorsion. MSCs significantly reversed the imbalance of glycolysis in sperm and testis induced by testicular torsion-detorsion, as evidenced by increasing the expression of phosphoglycerate kinase 2 and glyceraldehyde-3-phosphate dehydrogenase-spermatogenic, activating Akt, and increasing glycogen synthase kinase 3 (GSK3), which led to the increase in glycolysis cascades and ATP production. Human stem cell factor contributed the activation of Akt/GSK3 axis when sperm suffered from testicular torsion-detorsion-induced germ cell injury.

Conclusions

Local injection of MSCs into a testis damaged by testicular torsion-detorsion restores sperm function mainly through the improvement of sperm motility and energy. MSCs reversed the imbalance of glycogenesis and glycolysis in sperm by regulating Akt/GSK3 axis. Thus, MSCs may potentially rescue torsion-detorsion-induced infertility via local injection.

One-lung ventilation duration-dependent stress response in thoracotomies and the effect of a low-volume, high-frequency differentiated ventilation strategy on this response

Background

This study aims to investigate the effect of ventilation of the non-ventilated lung in patients undergoing one-lung ventilation by a separate low-tidal-volume (1 mL/kg) ventilator at high frequency (30/min) on preventing the effect of one-lung ventilation-associated oxidative damage.

Methods

The study included 45 patients (24 males, 21 females; mean age 54.6±7.7 years; range, 18 to 65 years) with an American Society of Anesthesiologists risk group of 1 to 2 and scheduled for elective thoracotomy. Patients were randomly divided into three groups as those due for thoracotomy without one-lung ventilation (group 1, n=15), those due for thoracotomy with one-lung ventilation (group 2, n=15), and those due for thoracotomy in whom both lungs were ventilated (group 3, n=15). Blood specimens were collected for ischemia-modified albumin, malondialdehyde, and lactate measurements one minute before one-lung ventilation (t0), 30 minutes after one-lung ventilation (t1), 60 minutes after one-lung ventilation (t2), and at postoperative 24th hour (t3). For group 1, t0 was defined as the time at which the thorax was opened.

Results

A statistically significant increase in ischemia-modified albumin, malondialdehyde, and lactate levels occurred in group 2 as the duration of one-lung ventilation increased (p<0.01). Plasma ischemia-modified albumin and malondialdehyde levels in group 3 were statistically significantly lower at t1, t2, and t3 compared with group 2 (p<0.01). Plasma lactate levels were significantly lower in group 3 at t1 (p<0.05) and t3 compared with group 2 (p<0.01).

Conclusion

Separate ventilation of the non-ventilated lung with low tidal volume and high frequency reduces the response to one-lung ventilation-associated oxidative stress in thoracic surgery.

N-acetylcysteine protects testicular tissue against ischemia/reperfusion injury via inhibiting endoplasmic reticulum stress and apoptosis

BACKGROUND

In animal models, endoplasmic reticulum (ER) stress has been reported to play a vital role in mediating ischemia/reperfusion (I/R) injury in certain organs, such as brain, liver, and intestine. However, there are a limited number of studies examining the relationship between ER stress and torsion and detorsion (T/D)-induced testicular injury.

OBJECTIVE

To investigate the effects of N-acetylcysteine (NAC) on ER-stress and apoptosis in an experimental testicular I/R injury model.

DESIGN

A non-blinded experimental study with three arms. Rats were divided into three groups: control group, T/D group, and NAC group. In the pretreatment of the NAC group, 20 mg/kg NAC was given intraperitoneally 30 min before detorsion. Tissue 4-hydroxynonenal (4-HNE), 78-kDa glucose-regulated protein (GRP78), and activating transcription factor 6 (ATF6) levels were determined using enzyme-linked immunosorbent assay. The apoptosis levels were evaluated using terminal deoxynucleotide transferase-mediated dUTP nick-end label assay.

RESULTS

In T/D group, tissue 4-HNE, GRP78, ATF6, and apoptotic index levels were significantly higher than control group. These increases were significantly reversed with NAC pretreatment.

DISCUSSION

There are some potential drugs that have been shown to reduce ER stress in the experimental ischemia model, and it is questioned that these drug candidates can be used as a therapeutic agent in the treatment of ischemic diseases in the near future. This study was not without limitations. First, the authors applied NAC only 20 mg/kg. In a future study, a dose-dependent assay should be performed to assess the likelihood of an additional testicular protective effect. One limitation of this research is also that in vivo studies cannot be extrapolated to possible effect in clinics. More experiments therefore need to be conducted to extrapolate the study findings to humans.

CONCLUSION

The study results showed that, after testicular torsion (TT), the ER stress-related apoptotic pathway plays a pivotal role in testicular injury. Further studies of other experimental models of TT may prove that NAC is a useful agent as an adjunctive treatment in surgical repair in human cases.

Protective Effects of Uncultured Adipose-Derived Stromal Vascular Fraction on Testicular Injury Induced by Torsion-Detorsion in Rats

Torsion‐detorsion (T/D)‐induced testicular injury may lead to male subfertility and even infertility. Stem cell therapy provides an alternative to attenuate testicular injury and promote spermatogenesis. Adipose‐derived stromal vascular fraction (SVF) can be acquired conveniently without in vitro expansion, which may avoid the potential risks of microbial contamination, xenogenic nutritional sources, etc., during cell culture. In this study, we investigate the protective effects of autologous uncultured SVF on testicular injury and spermatogenesis in a rat model of T/D. Animals were randomly divided into sham, T/D+ phosphate‐buffered saline, and T/D + SVF groups (18 rats in each group). SVF was isolated, labeled with lipophilic fluorochrome chloromethylbenzamido dialkylcarbocyanine, and transplanted into T/D testis by local injection. At 3, 7, 14, and 28 days F surgery, testicular tissue and serum samples were harvested for histopathological, immunohistochemical, Western blot, and enzyme‐linked immunosorbent assays. Histopathological findings demonstrated severe injury in the testis with decreased Johnsen's score led by T/D, while uncultured SVF reduced testicular injury and elevated the decreased score. Injected SVF cells were mainly integrated into interstitial region and seminiferous tubules, enhanced the secretion of basic fibroblast growth factor and stem cell factor in the testis, contributed to the declining level of malondialdehyde and restoration of hormonal homeostasis, and then reduced the injury of Leydig cells and germ cells, as well as promoting spermatogenesis. Our findings demonstrated that autologous uncultured SVF could protect the testis from testicular ischemia‐reperfusion injury and promote spermatogenesis, which provide significant clinical implications for the prevention of infertility induced by testicular T/D. stem cells translational medicine2019;8:383–391

The protective effect of low-energy shock wave on testicular ischemia-reperfusion injury is mediated by the PI3K/AKT/NRF2 pathway

AIMS

Testicular ischemia-reperfusion (IR) injury is the primary pathophysiological consequence of testicular torsion. Low-energy shock wave (LESW) is an effective treatment for certain diseases. The present study investigated whether LESW could improve on testicular IR injury in rats and examined the involved mechanism.

MAIN METHODS

Testicular reperfusion was induced in rats after 1-h ischemia. The first LESW treatment was performed 30 min prior to testicular reperfusion, and then every other day for another 3 applications. LY294002 was applied to investigate the involved mechanism. Testicular morphological changes and malonaldehyde (MDA) level were respectively assessed by hematoxylin-eosin staining. Western blot and thiobarbituric acid method. Western blot, real-time quantitative PCR and immunohistochemistry were performed to assess the apoptosis, the activation of phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B (PI3K/AKT) pathway the nuclear factor erythroid 2-related factor 2 (NRF2) and vascular endothelial growth factor A (VEGF-A) level in the testis of rats.

KEY FINDINGS

LESW improved testicular IR injury in rats. Moreover, LESW upregulated the phosphorylation levels of AKT and glycogen synthase kinase 3β (GSK-3β). Also, it upregulated the levels of nuclear NRF2, heme oxygenase 1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO-1) in these rats. Nevertheless, LY294002 blocked these protective effects. LESW also upregulated VEGF-A level in rats with testicular IR injury.

SIGNIFICANCE

This study demonstrated that LESW could ameliorate testicular IR injury in rats, which might be attributed to the activation of PI3K/AKT/NRF2 pathway. These findings suggested the potential of LESW in the treatment of testicular torsion.

Medical ozone therapy reduces oxidative stress and testicular damage in an experimental model of testicular torsion in rats

OBJECTIVE

Testicular torsion (TT) refers to rotation of the testis and twisting of the spermatic cord. TT results in ischemia-reperfusion (I/R) injury involving increased oxidative stress, inflammation and apoptosis, and can even lead to infertility. The aim of this study was to investigate the effect of ozone therapy on testicular damage due to I/R injury in an experimental torsion model.

MATERIALS AND METHODS

24 male Sprague-Dawley rats were divided into 3 groups; sham-operated, torsion/detorsion (T/D), and T/D+ozone. Ozone (1mg/kg) was injected intraperi-toneally 120 minutes before detorsion and for the following 24h. Blood and tissue samples were collected at the end of 24h. Johnsen score, ischemia modified albumin (IMA), total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) levels were determined.

RESULTS

Levels of IMA, TOS, OSI, and histopathological scores increased in the serum/tissue of the rats in the experimental T/D group. Serum IMA, TOS, and OSI levels and tissue histo-pathological scores were lower in the rats treated with ozone compared with the T/D group.

CONCLUSION

Our study results suggest that ozone therapy may exhibit beneficial effects on both biochemical and histopathological findings. Clinical trials are now necessary to confirm this.

Tissue Engineering to Improve Immature Testicular Tissue and Cell Transplantation Outcomes: One Step Closer to Fertility Restoration for Prepubertal Boys Exposed to Gonadotoxic Treatments

Despite their important contribution to the cure of both oncological and benign diseases, gonadotoxic therapies present the risk of a severe impairment of fertility. Sperm cryopreservation is not an option to preserve prepubertal boys’ reproductive potential, as their seminiferous tubules only contain spermatogonial stem cells (as diploid precursors of spermatozoa). Cryobanking of human immature testicular tissue (ITT) prior to gonadotoxic therapies is an accepted practice. Evaluation of cryopreserved ITT using xenotransplantation in nude mice showed the survival of a limited proportion of spermatogonia and their ability to proliferate and initiate differentiation. However, complete spermatogenesis could not be achieved in the mouse model. Loss of germ cells after ITT grafting points to the need to optimize the transplantation technique. Tissue engineering, a new branch of science that aims at improving cellular environment using scaffolds and molecules administration, might be an approach for further progress. In this review, after summarizing the lessons learned from human prepubertal testicular germ cells or tissue xenotransplantation experiments, we will focus on the benefits that might be gathered using bioengineering techniques to enhance transplantation outcomes by optimizing early tissue graft revascularization, protecting cells from toxic insults linked to ischemic injury and exploring strategies to promote cellular differentiation.

The protective effects of GYY4137 on ipsilateral testicular injury in experimentally varicocele-induced rats

The aim of the present study was to evaluate whether morpholin-4-ium 4 methoxyphenyl (morpholino) phosphonodithioate (GYY4137) exhibits a protective effect on ipsilateral testicular injury in experimentally varicocele (VC)-induced rats. A total of 48 rats were randomly divided into the following 6 groups (n=8 each): Group A (control group); group B (sham group); group C (VC group); group D (VC group administered 5 mg/kg/day GYY4137); group E (VC group administered 10 mg/kg/day GYY4137) and group F (VC group administered 20 mg/kg/day GYY4137). Indicators of oxidative stress, apoptosis and inflammation were measured to evaluate the effect of GYY4137 on ipsilateral testicular injury. Compared with groups A and B, rats in group C exhibited severe histological changes and an increase in oxidative stress, apoptosis and inflammation. By contrast, amelioration of testicular damage was evident in the group D, E and F that were treated with GYY4137. These results demonstrate that GYY4137 may be a promising therapy to treat VC as it alleviates oxidative stress, apoptosis and inflammation in experimentally VC-induced rats.

Antioxidants in experimental ischemia-reperfusion injury of the testis: Where are we heading towards?

Testicular torsion (TT) is a medical emergency that primary affects newborns and young adolescents. It causes testicular injury due to the torsion of the spermatic cord and its components, initially in the venous blood flow and finally in the arterial blood flow. Prompt diagnosis and early surgical management are necessary in managing this urgent situation. The process of the pathophysiological events in ischemia-reperfusion is multifactorial and deals with the perception of the oxidative stress responsible for the consequences of ischemia/reperfusion (I/R) stress following TT. Duration and severity of torsion also play a significant role in the oxidative stress. A detrimental result of the defense system of the testes takes place resulting finally in testicular atrophy and impaired function. Antioxidant factors have been experimentally studied in an effort to front this state. They have been classified as endogenous or exogenous antioxidants. Endogenous antioxidants comprise a structure of enzymic enzymatic and non-enzymic enzymatic particles presented within cytoplasm and numerous other subunits in the cells. Exogenous antioxidants include a variety of natural and pharmaceutical agents that may prevent or ameliorate the harmful effects of I/R injury. In this study we review those factors and their ability to enhance the oxidative status of the testis. A feature insight into where we are heading is attempted.

The possible protective effects of dipyridamole on ischemic reperfusion injury of priapism

PURPOSE

To investigate the protective effects against ischemia reperfusion injury of dipyridamole in a model of induced priapism in rats.

MATERIALS AND METHODS

Twenty-four male Sprague-Dawley rats were divided into four groups, control, P/R, P/R+DMSO and P/R+D. 3ml blood specimens were collected from vena cava inferior in order to determine serum MDA, IMA, TAS, TOS and OSI values, and penile tissue was taken for histopathological examination in control group. Priapism was induced in P/R group. After 1h, priapism was concluded and 30 min reperfusion was performed. In P/R+DMSO group 1ml/kg DMSO was administered intraperitoneally 30 min before reperfusion, while in P/R+D group 10mg/kg dipyridamole was administered intraperitoneally 30 min before reperfusion. Blood and penis specimens were collected after the end of 30 min reperfusion period. Sinusoidal area (μm2), tears in tunica albuginea and injury parameters in sinusoidal endothelium of penis were investigated.

RESULTS

Histopathological examination revealed no significant changes in term of sinusoidal area. A decrease in tears was observed in P/R+D group compared to P/R group (p<0.05). Endothelial injury decreased in P/R+D group compared to P/R group (p>0.05). There were no significant differences in MDA and IMA values between groups. A significant increase in TOS and OSI values was observed in P/R+D group compared to P/R group. A significant decrease in TAS levels was observed in P/R+D group compared to the P/R group.

CONCLUSIONS

The administration of dipyridamole before reperfusion in ischemic priapism model has a potential protective effect against histopathological injury of the penis.

Restoring Fertility with Cryopreserved Prepubertal Testicular Tissue: Perspectives with Hydrogel Encapsulation, Nanotechnology, and Bioengineered Scaffolds

New and improved oncological therapies are now able to cure more than 80% of cancer-affected children in Europe. However, such treatments are gonadotoxic and result in fertility issues, especially in boys who are not able to provide a sperm sample before starting chemo/radiotherapy because of their prepubertal state. For these boys, cryopreservation of immature testicular tissue (ITT) is the only available option, aiming to preserve spermatogonial stem cells (SSCs). Both slow-freezing and vitrification have been investigated to this end and are now applied in a clinical setting for SSC cryopreservation. Research now has to focus on methods that will allow fertility restoration. This review discusses different studies that have been conducted on ITT transplantation, including those using growth factor supplementation like free molecules, or tissue encapsulation with or without nanoparticles, as well as the possibility of developing a bioartificial testis that can be used for in vitro gamete production or in vivo transplantation.

Short-term Effects of Date Palm Extract (Phoenix dactylifera) on Ischemia/Reperfusion Injury Induced by Testicular Torsion/Detorsion in Rats

Background:

Antioxidants are potent scavengers of free radicals and have beneficial effects on human health.

Objective:

The aim of this study was to investigate the potential protective antioxidant activity of the edible portion of date fruit extract in an experimental testicular torsion/detorsion (T/D) model in rats.

Materials and Methods:

To investigate the potential protective effects of date palm (DP), 30 male Spraque-Dawley rats were divided into three groups: sham-operated, T/D, and T/D + DP-treated (500 mg/kg, PO) groups. Testicular ischemia was induced via keeping the left testis under 720° clockwise torsion for 2 h (h), afterward, detorsion was performed. All rats were sacrificed 4 h after detorsion. Serum malondialdehyde (MDA) concentration, total oxidative status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), and histopathological damage score were evaluated.

Results:

Serum MDA, TOS, and OSI levels rose significantly in the T/D group. These values were lower in the T/D + DP group. TAS values decreased significantly in T/D group and rose in T/D + DP group. Severe injury was seen in the twisted testes of T/D group. In contrast, ipsilateral-twisted testicular tissue in the DP-treated group showed moderate-to-mild changes. Contralateral testicular tissue in the T/D group had a mild-to-moderate tissue injury; meanwhile, treated group revealed normal-to-mild changes. Spermatogenesis was significantly improved in DP-treated group when compared with the T/D group.

Conclusion:

The findings suggest a possible protective effect of DP against testicular oxidative damage induced by T/D; however, more detailed studies are warranted.

SUMMARY

Given the presence of several phenolic compounds possessing high antioxidant activity in DP, it could potentially be used to reduce testis ischemia/reperfusion-induced damage.

Abbreviations Used: TAS: Total antioxidant status,TOS: Total oxidative status; OSI: Oxidative stress index; MDA: Malondialdehyde; C: Congestion; H: Hemorrhage, E: Edema; SG: Sloughed germinal cells; SA: Spermatogenesis arrest; STD: Seminiferous tubules disorganization; STA: Seminiferous tubules atrophy; G: Giant cells; T/D: Torsion/detorsion; DP: Date palm

Effectiveness of lycopene on experimental testicular torsion

AIM

We aimed to demonstrate the long term effectiveness of lycopene, a precursor of vitamin A, on the testes for ischemia-reperfusion injury.

MATERIALS AND METHODS

Seventy male Wistar albino rats were used for this experiment. The rats were divided into seven groups. Group 1 served as the control group; group 2 was sham-operated; group 3 received 20mg/kg/day lycopene (intraperitoneally); in group 4, the right testes of rats were kept torted for 2hours and then were detorted and the animals lived for three days; in group 5, the right testes of rats were kept torted for 2hours and then were detorted and the animals lived for ten days; in group 6, the right testes of the rats were kept torted for 2hours and then detorted and the animals received 20mg/kg/day lycopene (intraperitoneally) for three days; in group 7, the right testes of the rats were kept torted for 2hours and then were detorted and the animals received 20mg/kg/day lycopene (intraperitoneally) for ten days. Lycopene was used intraperitoneally. Some of the testes tissues were used for biochemical analyses and the other tissues were used for histological procedures. The Johnsen's score was used for seminiferous tubule deterioration. The TUNEL method was utilized to show apoptosis of testicular tissue. Testosterone levels were measured from blood samples and SOD, MDA, TNF-α, IL-1β and IL-6 measurements were recorded from tissue samples. The results were analyzed statistically.

RESULTS

In groups 1, 2 and 3 there was normal testicular structure. Rats in groups 4 and 5 had damaged testicular tissues. In groups 6 and 7, in which we used lycopene, the testes were not better than those in groups 4 and 5. The MSTD and JTBS values were better in group 6, but not in group 7 among the torsion groups. As a result, MDA, SOD, TNF-α and IL-1β were increased and serum testosterone and IL-6 levels were decreased in groups 4 and 5 compared to group 1. There was no improvement in the groups treated with lycopene for therapeutic purposes.

CONCLUSION

It was shown that lycopene, as an antioxidant agent, is not effective for testicular torsion in the long term. This study can be considered as a preliminary study showing the need for further researches using different antioxidant agents to determine their long term effects in ischemia-reperfusion injuries in an appropriate experimental design.

N-acetylcysteine leads to greater ovarian protection than enoxaparin sodium in a rat ovarian torsion model

This study evaluated the effects of N-acetylcysteine (NAC) and enoxaparin on ovarian tissue preservation, ovarian reserve and oxidative damage following ovarian torsion/detorsion injury. Rats were divided into four groups (n = 6/group): control; ischaemia/reperfusion (I/R); I/R + NAC; I/R + enoxaparin. Twenty-four hours after detorsion, ovarian tissues were collected for histopathological analysis and measurement of tissue 8-OHdG, GSH, MDA, MPO and SOD concentrations, as well as pre- and post-operative circulating AMH concentrations. Administration of NAC resulted in more pre-antral follicles compared with enoxaparin treatment and haemorrhage and follicle cell degeneration were more pronounced in I/R + enoxaparin group than I/R + NAC group. Both NAC and enoxaparin led to a significant reduction in ovarian tissue 8-OHdG (P = 0.004 and P = 0.01, respectively) and MPO (P = 0.013 and P = 0.023, respectively) concentrations compared with I/R group, indicating a protective effect against I/R oxidative damage. Only NAC-treated animals showed a significant increase in GSH and SOD concentrations and decrease in MDA concentrations compared with I/R group (P = 0.007, P = 0.024 and P = 0.026, respectively). These results indicate that NAC is more effective than enoxaparin in minimizing ovarian damage and preserving ovarian reserve following ovarian torsion.

In Search of Better Spermatogonial Preservation by Supplementation of Cryopreserved Human Immature Testicular Tissue Xenografts with N-acetylcysteine and Testosterone

Controlled slow-freezing is the procedure currently applied for immature testicular tissue (ITT) cryobanking in clinical practice. Vitrification has been proposed as a promising alternative, with a view to better preserve the spermatogonial stem cells for future fertility restoration by autografting in young boys suffering from cancer. It appears that besides the potential influence of the cryopreservation technique used, the transplantation procedure itself has a significant impact on spermatogonial loss observed in ITT xenografts. Eighteen ITT pieces issued from 6 patients aged 2–15 years were used. Fragments of fresh tissue (serving as ungrafted controls), frozen-thawed tissue, frozen-thawed tissue supplemented with N-acetylcysteine (NAC), and frozen-thawed tissue supplemented with testosterone xenografted to nude mice for 5 days were compared. Upon graft removal, histological and immunohistochemical analyses were performed to evaluate spermatogonia, intratubular proliferation, and intrinsic and extrinsic apoptosis. A significant decrease in the integrity of intact seminiferous tubules was found in all three grafted groups. Spermatogonia were observed by immunohistochemistry in all grafted groups, with recovery rates of 67, 63, and 53%, respectively, for slow-frozen tissue, slow-frozen tissue supplemented with NAC, and slow-frozen tissue supplemented with testosterone. Apoptosis evidenced by active caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling was similar in all grafts. The study is limited by the low availability of ITT samples of human origin, and no clear impact of graft supplementation was found. The mouse xenotransplantation model needs to be refined to investigate human spermatogenesis in human ITT grafts.

Effects of apocynin, an NADPH oxidase inhibitor, on levels of ADMA, MPO, iNOS and TLR4 induced by myocardial ischemia reperfusion

PURPOSE

In this study, the effects of apocynin, an NADPH oxidase inhibitor, on the levels of inducible nitric oxide synthase (iNOS) and the toll-like receptor 4 (TLR4), which are inflammatory mediators in myocardial ischemia-reperfusion (MIR) injury, and myeloperoxidase (MPO), which is the indicator of neutrophil infiltration and the endogenous nitric oxide synthase inhibitor asymmetric dimethyl arginine (ADMA) increasing with oxidative stress were investigated.

METHODS

MIR injury was accomplished by the application of occlusion for 30 minutes and reperfusion for 120 minutes in the left anterior descending artery (LAD). In the study, 21 Sprague-Dawley male rats were divided into three groups: a sham group (n = 7); a MIR group (n = 7); and a MIR + apocynin treatment group (n = 7, before the procedure, an intraperitoneal administration of 10 mg/kg of apocynin for 15 days). After reperfusion, iNOS, TLR4, MPO and ADMA levels in myocardial tissue were measured by ELISA.

RESULTS

While myocardial TLR4, MPO and ADMA levels increased in the MIR group, these parameters were found to be decreased significantly in the group treated with apocynin. Although iNOS levels showed an increase in the MIR group compared to the sham group and a reduction in the MIR+apocynin group, there was no statistically significant difference between the groups.

DISCUSSION

In our study, the effect of the treatment of apocynin in MIR on ADMA, MPO, iNOS and TLR4 levels in myocardial tissue was shown for the first time. It is thought that apocynin treatment may show a protective effect in MIR injury by affecting oxidative stress (ADMA) and inflammatory parameters (iNOS, MPO).

The association between ischaemia-modified albumin levels in umbilical vein and intrauterine growth restriction

Intrauterine growth restriction (IUGR) is one of the most common problems in obstetrics. Ischaemia-modified albumin (IMA), a product deriving from albumin as a result of the modification by oxidative free radicals in response to hypoxia, was previously used as a marker of ischaemia in acute coronary syndrome. We performed this study to determine whether umbilical venous IMA levels are associated with IUGR. A total of 40 pregnancies with IUGR were compared with 40 of normal fetal development. Blood samples were obtained from the umbilical vein after delivery. IMA levels in the IUGR group were higher than in the control group (78.74 ± 6.87 vs 74.43 ± 7.84 U/ml, respectively, p = 0.011). An elevated IMA level was associated with IUGR (OR: 1.079, 95% CI: 1.000-1.163, p = 0.049). We suggest that IMA, which was formerly proved to arise in ischaemic conditions, may also be a valuable marker in perinatal hypoxia and IUGR detection.

Mechanisms of testicular torsion and potential protective agents

Testicular torsion is a urological emergency most commonly seen in adolescence, involving a decrease in blood flow in the testis resulting from torsion of the spermatic cord that can result in gonad injury or even loss if not treated in time. Testicular ischaemia-reperfusion injury represents the principle pathophysiology of testicular torsion, with ischaemia caused by twisting of the spermatic cord, and reperfusion on its subsequent release. Many cellular and molecular mechanisms are involved in ischaemia-reperfusion injury following testicular torsion. Studies have investigated the use of pharmacological agents as supportive therapy to surgical repair in order to prevent the adverse effects of testicular torsion. Numerous substances have been proposed as important in the prevention of post-ischaemia-reperfusion testicular injury. A range of chemicals and drugs has been successfully tested in animal models for the purpose of mitigating the dangerous effects of ischaemia-reperfusion in testis torsion.

Investigation of tyrphostin AG 556 for testicular torsion-induced ischemia reperfusion injury in rat

OBJECTIVE

To investigate the effects of tyrphostin AG 556, a tyrosine kinase inhibitor (TKI) in an experimental model of testicular ischemia-reperfusion (I/R) injury.

MATERIAL AND METHODS

Twenty-four adult male rats were randomly divided into four groups (n = 6): sham, torsion/detorsion (T/D), T/D + dimethylsulfoxide (DMSO) (vehicle group), and T/D + DMSO + tyrphostin AG 556. Testicular torsion was achieved by rotating the left testis 720° clockwise for 4 h. Thirty minutes before detorsion, 3 mg/kg tyrphostin AG 556 was injected transperitoneally in the AG 556 group and DMSO was injected transperitoneally in the DMSO group. After 2 h of reperfusion arterial blood samples were collected for biochemical analysis for malondialdehyde (MDA), ischemia modified albumin (IMA), SCUBE1 (signal peptide-CUB [complement C1r/C1s, Uegf, and Bmp1] and EGF [epidermal growth factor] like domain-containing protein 1), total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) parameters, and ipsilateral orchiectomies were performed for histopathological examination based on the semi-quantitative Johnsen's mean testicular biopsy score (MTBS) in all groups.

RESULTS

Tyrphostin AG 556 exhibited a protective effect against I/R injury in testicular torsion. Of the biochemical parameters evaluated as a result of testicular I/R, IMA, MDA, and TOS levels were significantly elevated. There was no significant difference in terms of these biochemical parameters between the sham and AG 556 groups. Significant histopathological injury was determined by comparing the T/D and sham groups. According to histopathological injury scores, significant differences were determined between T/D and AG 556 groups and between AG 556 and sham groups. AG 556 had a superior improving effect on Johnsen's scores than DMSO.

CONCLUSIONS

Our results suggest that the use of tyrphostin AG 556 prior to testicular reperfusion has a protective effect against testicular I/R injury.

The short term effects of resveratrol on ischemia-reperfusion injury in rat testis

PURPOSE

The purpose of this study was to identify changes taking place in the rat testis at the 24th hour of reperfusion following testicular torsion and to evaluate the effects of resveratrol (RSV), a powerful antioxidant, in preventing these changes using novel biochemical parameters and histopathology.

METHODS

Eighteen adult male rats were divided into three groups: Sham-operated (S), torsion/detorsion (T/D), and T/D+RSV groups. In the T/D group, testicular ischemia was achieved by rotating the left testis 720° clockwise for 4h. In the T/D+RSV group, 20mg/kg RSV was administered intraperitoneally 30 min before detorsion. All rats were sacrificed 24h after detorsion. Serum and tissue malondialdehyde (MDA) concentrations, ischemia modified albumin (IMA), total oxidative status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), and histopathological damage score were analyzed.

RESULTS

Serum MDA, IMA, TOS, and OSI levels rose significantly in the T/D group. Serum MDA and IMA values were lower in the T/D+RES groups, but not significantly. OSI and TOS values were lower in the T/D+RES group, and the difference was significant. TAS values decreased significantly in the T/D group and rose in the T/D+RSV group, but not significantly. Ipsilateral tissue MDA values were significantly elevated in the T/D group and decreased in the T/D+RSV group, but not significantly. Apoptosis and histopathological damage increased significantly in the T/D group and decreased significantly in the T/D+RSV group. In the contralateral testis, apoptosis increased significantly in the T/D group. It decreased significantly in the T/D+RSV group.

CONCLUSIONS

Our findings show that RSV had a protective effect against oxidative damage induced with a testicular T/D model, especially at the antiapoptotic and histopathological level. OSI may be a good guide to the clinical status of testicular T/D.

Protective effect of N-acetylcysteine against ischemia/reperfusion injury in rat urinary bladders

Ischemia/reperfusion (I/R) injury represents an important cause of bladder contractile dysfunction. One of the major causes leading to this dysfunction is thought to be reactive oxygen species formation. In this study, we investigated the potential benefit of N-acetylcysteine (NAC), a potent antioxidant that neutralizes free radicals, in a rat model of urinary bladder injury. NAC treatment rescues the reduction of contractile response to I/R injury in a dose-dependent manner. In addition, all levels of reactive oxygen species, lipid peroxidation, and NADPH-stimulated superoxide production in the I/R operation+NAC (I/R+NAC) group also decreased compared with a marked increase in the I/R operation+saline (I/R+S) group. Moreover, an in situ fluorohistological approach also showed that NAC reduces the generation of intracellular superoxides enlarged by I/R injury. Together, our findings suggest that NAC has a protective effect against the I/R-induced bladder contractile dysfunction via radical scavenging property.

The protective effects of grape seed extract on MDA, AOPP, apoptosis and eNOS expression in testicular torsion: an experimental study

OBJECTIVES

Grape seed proanthocyanidin extract (GSPE) is a potent antioxidant and a free radical scavenger. This study was designed to determine whether GSPE could protect against dysfunction and oxidative stress induced by torsion-detorsion injury in rat testis.

METHODS

A total of 45 male Wistar albino rats were divided into five groups: control group, sham group, torsion-detorsion (T/D) group, T/D + GSPE group, GSPE group. GSPE was administrated 100 mg/kg/day with oral gavage over seven days before torsion. Testicular torsion was performed for 2 h, and afterward, detorsion was performed for 2 h. The rats were decapitated under ketamine anesthesia, and their testes tissues were removed. Tissue malondialdehyde, advanced oxidation protein products levels, eNOS expression, apoptosis and histopathological damage scores were then compared.

RESULTS

Testicular torsion-detorsion caused significant increases in malondialdehyde level, apoptosis and eNOS expression level and caused a significant decrease in advanced oxidation protein product levels and testicular spermatogenesis in ipsilateral testes. GSPE prevented the rise in malondialdehyde, apoptosis and eNOS expression and improved testicular morphology and Johnsen's score.

CONCLUSIONS

As a result, testicular torsion gives rise to serious damage in testes and GSPE is a potent antioxidant agent in preventing testicular injury.