Protective effect of vascular endothelial growth factor on histologic changes in 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.

Testicular niche repair after gonadotoxic treatments: Current knowledge and future directions

The testicular niche, which includes the germ cells, somatic cells, and extracellular matrix, plays a crucial role in maintaining the proper functions of the testis. Gonadotoxic treatments, such as chemotherapy and radiation therapy, have significantly improved the survival rates of cancer patients but have also been shown to have adverse effects on the testicular microenvironment. Therefore, repairing the testicular niche after gonadotoxic treatments is essential to restore its function. In recent years, several approaches, such as stem cell transplantation, gene therapy, growth factor therapy, and pharmacological interventions have been proposed as potential therapeutic strategies to repair the testicular niche. This comprehensive review aims to provide an overview of the current understanding of testis damage and repair mechanisms. We will cover a range of topics, including the mechanism of gonadotoxic action, repair mechanisms, and treatment approaches. Overall, this review highlights the importance of repairing the testicular niche after gonadotoxic treatments and identifies potential avenues for future research to improve the outcomes for cancer survivors.

Potential Mechanism of Platelet-rich Plasma Treatment on Testicular Problems Related to Diabetes Mellitus

Diabetes mellitus is a condition of continuously increased blood glucose levels that causes hyperglycemia. This condition can result in disorders of various organs including testicular problems. The use of platelet-rich plasma (PRP) which is contained in several growth factors shows its potential in overcoming testicular problems. This literature review study was conducted to identify the potential of PRP in overcoming various testicular problems due to diabetic conditions.

Protective Effect of Portulaca oleracea on Streptozotocin-Induced Type I Diabetes-Associated Reproductive System Dysfunction and Inflammation

Background: Type-one diabetes (T1D), a chronic autoimmune disease with marked inflammatory responses, is associated with infertility complications and implications. Based on the anti-diabetic, antioxidant, and anti-hyperlipidemic potential of Portulaca oleracea (PO), this study aimed to evaluate the protective effect of this plant extract on streptozotocin-induced type-I-diabetes-associated reproductive system dysfunction and inflammation. Methods: Male rats were randomly divided into four experimental groups: control, diabetic, and treatment/s (PO extract at 100 or 300 mg/kg/daily). Then food and water consumption, body, testis and epididymis weights, histopathological evaluation, seminiferous tubules diameter, sperm count and motility, glucose levels, sex hormones, and inflammatory and oxidative stress markers were evaluated. Results: Our results showed that streptozotocin-induced diabetes significantly increased food and water consumption; increased glucose, MDA, TGF-β1, and TNF-α levels; and decreased the seminiferous tubules diameter, sperm count and motility, levels of LH, testosterone, total thiol, VEGF, and SOD activity. Interestingly, PO extract (phytochemically characterized by using liquid chromatography–mass spectrometry to detect bioactive molecules) significantly ameliorated these parameters and histopathological indexes’ damage in rats. Conclusion. Even if more preclinical assessments are needed to better characterize the mechanism/s of action, the results of this study will pave the way for the rational use of PO on diabetic-associated clinical complications and implications.

Effect of low energy shock wave on testicular microenvironment homeostasis in rats

OBJECTIVE

To further investigate whether two sets of low-energy extracorporeal shock waves (LESWs) impulse parameters, i.e., 0.02 mJ/mm² for 500 impulses and 0.04 mJ/mm² for 500 impulses, which have been shown to directly affect the testes, can promote testicular spermatogenesis or positively regulate homeostasis of the testicular microenvironment.

METHODS

(1) Twenty-four experimental rats were randomly divided into a 0.02 mJ/mm² 500 impulses group (L1 group), a 0.04 mJ/mm² 500 impulses group (M1 group), a sham intervention group (S group) and a blank control group (N group). The experiment period was 8 weeks. (2) Apoptosis of the spermatogenic cells in the left testicle was detected by the TUNEL method, VEGF and eNOs protein expression was detected by immunohistochemistry, and histomorphological changes were observed in PAS-stained sections. Moreover, the morphologies of the spermatogenic tubules and testicular stroma were quantitatively analyzed by stereological analysis. The right testicle was used for Western blot detection of the protein expression levels of Bax, Cytochrome C, Caspase-3, Bcl-2, VEGF and eNOs.

RESULTS

Compared with the other three groups, the rate of M1 testicular germ cell apoptosis induced by shock treatment was higher, the expression levels of proapoptotic proteins increased significantly while that of the antiapoptotic protein was lower, and the suppression of cell proliferation correlated with the protein expression levels. Additionally, with respect to the absolute volume of the seminiferous tubules, the absolute interstitial testicular volume notably increased, producing a series of biological effects working against testicular sperm production and function. However, there was no significant difference between the L1 group and the N and S groups.

CONCLUSIONS

LESWs treatment with impulse parameters of 0.02 mJ/mm² for 500 impulses showed a better protective effect on testicular spermatic function in rats and has a positive regulatory biological effect.

The effect of protection of platelet-rich plasma against experimental ischemia/reperfusion injury in the rat ovary on in vitro fertilization outcomes

OBJECTIVE

Ovarian torsion is a common cause of local ischemic damage, reduced follicular activity and infertility. This study aimed to investigate how well platelet-rich plasma (PRP) protects against experimental ischemic (I) and ischemia-reperfusion (I/R) injury in rat ovaries and its effect on in vitro fertilization (IVF) outcomes.

METHOD

Fifty-six adult female Sprague-Dawley albino rats were randomly assigned to six groups of eight animals each: Sham, Ischemia, I/R, Sham + PRP, I + PRP, and I/R + PRP. The remaining eight animals were used to prepare the PRP. The ischemia groups were subjected to bilateral adnexal torsion for 3 h, while the I/R and I/R + PRP groups received subsequent detorsion for 3 h. Intraperitoneal (i.p.) PRP was administered 30 min prior to ischemia (I + PRP) or reperfusion (I/R + PRP). The ovaries were stimulated through an intraperitoneal injection of 150-300 internal units of IU/kg PMSG. After ovulation induction, oocytes were taken from the ovaries, and IVF was performed.

RESULTS

The number of MII oocytes reached the highest number with 4.63 ± 0.74 in the S group and had the lowest number with 0.50 ± 0.53 in the I/R group. There were statistically significant differences for the number of embryos obtained on the second day between the I and I + PRP groups and the I/R and I/R + PRP groups (p = 0.000). In comparing anti-Müllerian hormone 1 (AMH1) and AMH2 values within the group, the highest decrease was observed in the I and I/R groups.

CONCLUSION

PRP is effective in minimizing ovarian damage and preserving ovarian reserves following ovarian torsion.

A review of the protective effects of quercetin-rich natural compounds for treating ischemia-reperfusion injury

Ischemia-reperfusion (IR) injury causes dysfunction of tissues and organs, and oxidative stress plays an important role. During IR, reactive oxygen species (ROS) are increased. Antioxidants are used to decrease ROS associated with IR. We review the protective effects of quercetin-rich natural antioxidants against IR. We searched PubMed, ScienceDirect, Scopus and Cochrane databases using the keywords: ischemic reperfusion, quercetin, antioxidant and herbal medicine. The effects of quercetin during IR have been reported for animal models in vitro and in vivo. Quercetin-rich plants including Abelmoschus esculentus, coriander, Hypericum perforatum, onion, Psidium guajava, buckwheat and Rosa laevigata Michx have been used to reduce oxidative stress damage to various organs during IR.

Epithelial growth factor and decompressive testicular fasciotomy to control ischemia reperfusion injury in rats

PURPOSE

Testicular torsion is an urological emergency and an important cause of male infertility. Recent studies have shown that not only ischemia, but also the restoration of blood flow creates a deleterious situation for the testis. The goal of this work was to evaluate the role of systemic epithelial growth factor application and its association with decompressive fasciotomy in tissue recovery of the testes undergoing the torsion of the spermatic cord.

METHOD

Torsion of the spermatic cord was induced in 40 Wistar pubescent testes for a period of 4 h. At the time of detorsion systemic epithelial growth factor and decompressive fasciotomy were applied as treatment alternatives. After 21 days, the testicles were examined macro and microscopically.

RESULTS

The variables evaluated were weight, testicular volume and the degree of histological alterations by optical microscopy. The rate of healing of testicular torsion showed significant difference between the groups. It was noted that in terms of testicular weight and volume the animals treated with systemic epithelial growth factor resembled the control group and had a better histological classification than the other groups. The mean Johnsen score was significantly higher in the group treated with systemic growth factor and decompressive testicular fasciotomy than in the group without fasciotomy. No significant changes were noted in the contralateral testes.

CONCLUSION

Although decompressive testicular fasciotomy improved spermatogenesis, recovery was limited. Systemic epithelial growth factor administered in combination with decompressive testicular fasciotomy was more effective for spermatogenesis than fasciotomy alone. Administering epithelial growth factor after reperfusion might have the potential to decrease long-term histologic damage after testicular torsion. The combination of decompressive testicular fasciotomy and epithelial growth factor had a synergistic effect on the healing of these testes.

The protective effect of Ganoderma lucidum on testicular torsion/detorsion-induced ischemia-reperfusion (I/R) injury

Purpose

To investigate the protective effect of Ganoderma lucidum on testicular torsion/detorsion (T/D)-induced ischemia-reperfusion (I/R) injury.

Methods

Thirty male Wistar albino rats were randomly categorized into 3 groups: Group 1: sham, Group 2 ( T/D): 2,5 hours of ischemia and 7 days of reperfusion, Group 3 (T/D+ G. lucidum ): 2,5 hours of ischemia and 7 days of reperfusion and 7 days of 20 mg/kg via gastric gavage G. lucidum polysaccharides per day. Biochemical assays of Malondialdehyde (MDA), superoxide dismutase (SOD), Catalase (CAT), Glutathione (GSH) levels , histopathology and expression levels of VEGF and Bcl-2 with immunohistochemical methods were examined in testicular tissue.

Results

G. lucidum treatment was found to have prevented the T/D-induced I/R injury by decreasing MDA levels of the testis. SOD, CAT and GSH activities were decreased in group 2, while they were increased in group 3 (p<0.001) and significant improvement in the tube diameter was observed in group 3. Bcl-2-positive germinal cells were lowered in group 3 compared to the group 2. VEGF expression showed an increase in group 2, whereas it decreased in group 3.

Conclusion

The antioxidant G. lucidum is thought to induce angiogenesis by reducing the apoptotic effect in testicular torsion-detorsion.

Safety parameters of in vivo low-energy shock waves and their impact on adult rat testes

Low-energy shock waves (LESWs) have been widely used in the intervention of a subset of diseased tissues and organs with good results. However, it is unclear whether they can be used directly to intervene in the testes. Therefore, the aim of this study was to determine a relatively safe energy density and impulse number for rat testes. A total of 176 male rats were randomly and equally assigned to different intervention groups. Among them, 144 rats were assigned to 18 shock subgroups with different energy densities (0.02, 0.04 and 0.06 mJ/mm²), different impulse numbers (500, 1000 and 1500 impulses) and different shock periods (2 and 8 weeks). The remaining 32 rats were divided into the sham intervention (S) groups and the blank control (N) groups with observation periods of 2 weeks and 8 weeks. One day after the last LESWs intervention, all the rats were weighed, and the concentrations of reproductive endocrine hormones were measured, the semen quality and testicular tissue oxidative stress levels were analyzed, and histomorphology and ultrastructures were observed. We found that there were no significant differences in the whole-body physiological state, testicular tissue morphology, oxidative stress state and sperm quality between the L1 shock group and the corresponding S group and N group (all p˃0.05, respectively). However, the other parameters of the shock groups caused different degrees of damage to the structure and function of rat testes, and the whole-body physiological state was also adversely affected. This study demonstrated that LESWs with an energy density of 0.02 mJ/mm² and 500 impulses had no adverse effects on the rat testes.

Effects of L-carnitine and betamethasone on ischemia-reperfusion injuries and sperm parameters following testicular torsion in a rat model

Testicular torsion is a consequence of spermatic cord twisting which causes progressive damage to the structure of the testis and reduces sperm quality and usually results in infertility. In the present study, with the assumption of the protective effects of L-carnitine and betamethasone against ischemia-reperfusion (IR) injuries, their effects on twisted testicles were evaluated and compared. Twenty Wistar rats were randomly divided into four groups and used in this study. Except for the Sham (S) group, testicular IR was induced surgically in three other groups, including Control (C), Betamethasone (BM), and L-carnitine (LC) groups. Betamethasone and L-carnitine were injected before detorsion in the BM and LC groups, respectively. After twelve hours of reperfusion, the testicles were detached, and prepared for sperm parameters evaluation such as sperm count, motility, viability, morphology, and chromatin quality, and histopathologic evaluations, including mean seminiferous tubular diameter (MSTD), germinal epithelial cell thickness (GECT), and Johnsen's mean testicular biopsy scoring (MTBS). The MSTD, GECT, and healthy sperms in the C group were significantly lower than the other groups, while the BM and LC groups were significantly different from others in MTBS. The number of sperms and sperm motility in the BM group was significantly higher than the C group. Sperm viability in the BM and LC groups were significantly higher than the C group. The results of this study showed that both L-carnitine and betamethasone similarly can be effective in treating testicular IR injuries.

Vitamin E improves testicular damage in streptozocin-induced diabetic rats, via increasing vascular endothelial growth factor and poly(ADP-ribose) polymerase-1

The precise mechanism by which diabetes impairs spermatogenesis and testicular function is not exactly known. Vascular endothelial growth factor (VEGF) and poly(ADP-ribose) polymerase-1 (PARP-1) are important for germ cell homeostasis and repair of DNA respectively. The aim of this study was to investigate the correlation between diabetes-induced testicular damage and testicular VEGF and PARP-1 expression and the possible protective role of vitamin E supplementation. A total of 45 male Wistar albino rats were randomly divided into three groups: Group I (nondiabetic rats), Group II (streptozocin-induced diabetic rats) and Group III (streptozocin-induced diabetic rats treated orally with 0.4 mg/kg vitamin E). Five weeks later, testicular tissue was used for assessment of MDA concentration by colorimetry, histopathological examination and immunostaining for PARP-1 and VEGFIn diabetic rats, testicular weight, seminiferous tubule diameter and germinal epithelial thickness were decreased, basement membrane was thickened and Johnsen score decreased. Reduced VEGF and PARP-1 immunostaining were associated with decreased Johnsen score in diabetic rats. Vitamin E administration was protective against oxidative stress-associated damage evidenced by lower MDA levels, improved testicular weight, spermatogenesis and higher immunostaining for VEGF and PARP-1. Testicular VEGF and PARP-1 might therefore be helpful biomarkers for diabetic testicular damage. Administration of vitamin E may have a protective role against diabetes-induced testicular damage.

Pathological effect of arterial ischaemia and venous congestion on rat testes

Many studies on various organs have concluded that venous congestion (VC) causes severe organ dysfunction with elevation of oxidative stress relative to that of arterial ischaemia (AI). However, a comparison of the pathological effects of AI and VC on the testes has not been conducted. In this study, models of AI and VC and their reperfusion in rat testes, respectively, were developed and analysed. Testicular arteries or veins were interrupted for 6 h, re-perfused and kept for 4 weeks; the effects on the testes were then evaluated. Severe spermatogenic disturbances were observed at 4 weeks after reperfusion in AI but not in VC. At 6 h after blood flow interruption, oxidative stress was significantly increased and germ cells were severely damaged in AI compared with those in VC. RT-PCR analyses revealed that haem oxygenase-1, which exhibits anti-oxidative effects, and vascular endothelial growth factor-A, which exhibits vasculogenic effects, were significantly increased in VC but not in AI. Surprisingly, the results of our experiment in rat testes differed from those of experiments in previous studies performed in other organs. Oxidative stress in testes was more easily elevated by AI than it was by VC, explainable by the different experimental conditions.

Ferulic acid prevents lead-induced testicular oxidative stress and suppressed spermatogenesis in rats

Lead affects multiple organ systems including testis. We investigated the effects of ferulic acid (FA) on lead-induced oxidative stress and spermatogenesis suppression in rats. Animals received lead acetate (500 mg/L in drinking water) and/or FA (50 mg/kg, i.g.) for eight weeks. Lead increased testicular malondialdehyde (MDA) and nitrite levels and decreased glutathione (GSH) content and catalase (CAT) activity. Lead decreased testis weight and testosterone level. Sperm parameters decreased in lead group. FA ameliorated the decreased testis weight, serum testosterone as well as sperm count, viability, motility and normal morphology in lead group. FA improved antioxidant capacity as well as sperm count, viability, motility and normal morphology. FA decreased Johnsen's mean testicular biopsy score (MTBS) criteria by restoring degeneration, atrophy and tubular disarrangement. FA also normalised spermatogonia, spermatocytes and spermatids numbers in lead group and led to increases in number of Leydig and Sertoli cells. FA showed beneficial effects in lead-induced testicular oxidative stress and spermatological disorders, through inhibiting lipid peroxidation and enhancing antioxidant defence systems. The positive effects of FA on Leydig cells may be involved in restoring testosterone levels in lead group. FA can be considered a potential candidate to protect testis against the deleterious effect of lead intoxication.

Effects of melatonin and metformin co-administration on testicular ischemia/reperfusion injury in rats

INTRODUCTION

Torsion of the spermatic cord is a common urologic emergency among infants and adolescents. It requires early diagnosis and surgical intervention to prevent subfertility and infertility.

OBJECTIVE

The aim of this study was to investigate the effects of melatonin (MEL) and metformin (MET) co-administration on experimental testicular ischemia/reperfusion (I/R) injury in rats.

MATERIAL AND METHODS

Fifty male Wistar rats were randomly divided into five experimental groups (n = 10), as follows. Group 1 was sham operated. In group 2, 1-hour ischemia was induced by the left testicular artery and vein clipping followed by 7 days of reperfusion. In groups 3 and 4, MEL (3 mg/kg) or MET (100 mg/kg) was administered orally for 7 days via oral gavage after ischemia, and in group 5 both agents were co-administered. At the end of trial, the left testis was removed for histological analysis and oxidative stress measurement. Histological findings in seminiferous tubule were evaluated according to Johnsen's scoring system.

RESULTS

I/R reduced superoxide dismutase (SOD) activities and testicular Johnsen's scores accompanied by an elevation in malondialdehyde (MDA) and myeloperoxidase (MPO) levels (p < 0.05). MEL and MET, and their combination restored SOD activity, tissue scores, MDA and MPO levels (p < 0.05). There was no significant difference among individual or combined treatment of these parameters (p > 0.05).

DISCUSSION

In the present experiment, using a rat model it has been demonstrated that testicular I/R caused a significant increase in testicular injuries. This was in accordance with previous studies that have demonstrated the effect of I/R in testicular tissue. Treatment of MEL and MET had a benefit effect, but, there was no significant difference among individual or combined treatment.

CONCLUSIONS

The results of the present study suggest that MEL and MET may be useful for protecting the testes from the I/R injury. However, the combined use of these agents does not further increase the protection from this damage.

Protective effect of pterostilbene on testicular ischemia/reperfusion injury in rats

PURPOSE

To evaluate protective effect of pterostilbene against testicular ischemia/reperfusion (I/R) injury, which results in increased formation of oxidative stress, leading to testicular apoptosis and impaired spermatogenesis.

METHODS

Thirty two pubertal male Sprague-Dawley rats weighing 180-220g were selected and randomly divided into the following four groups: group A (normal control group), group B (sham-operated group), group C (induced I/R injury group), group D (induced I/R injury group receiving pterostilbene treatment). Johnsen's scores and mean seminiferous tubule diameters were evaluated for histopathologic assessment; germinal cell apoptosis was evaluated by the transferase dUTP nick end labeling (TUNEL) assay and immunohistochemistry for caspases. Malondialdehyde (MDA) levels were assessed as an indicator of oxidative stress and total antioxidant capacity (TAC) was measured.

RESULTS

Germ cell apoptosis and MDA level significantly increased whereas TAC significantly decreased in group C; moreover, abnormal morphology and impaired spermatogenesis were observed in group C. In contrast, treatment with pterostilbene inhibited lipid peroxidation and apoptosis induced by ROS and restored the antioxidant capacity in group D.

CONCLUSIONS

These results show that treatment with pterostilbene may be a promising therapy for testicular I/R injury.

VEGF released from a fibrin biomatrix increases VEGFR-2 expression and improves early outcome after ischaemia-reperfusion injury

Skeletal ischaemia-reperfusion (I-R) injury may influence patient outcome after severe vascular trauma or clamping of major vessels. The aim of this study was to observe whether locally applied vascular endothelial growth factor (VEGF) in fibrin could induce the expression of VEGF-receptor-2 (VEGFR-2) and improve the outcome after I-R injury. Transgenic mice expressing VEGFR-2 promoter-controlled luciferase were used for the assessment of VEGFR-2 expression. Ischaemia was induced for 2 h by a tension-controlled tourniquet to the hind limb, followed by 24 h of reperfusion. The animals were locally injected subcutaneously with fibrin sealant containing 20 or 200 ng VEGF; control animals received no treatment or fibrin sealant application. In vivo VEGFR-2 expression was quantified upon administration of luciferin at several observation times. For oedema and inflammation quantification, wet:dry ratio measurements and a myeloperoxidase assay of the muscle tissue were performed. Laser Doppler imaging showed that ischaemia was present and that the blood flow had returned to baseline levels after 24 h of reperfusion. VEGFR-2 expression levels in the fibrin + 200 ng VEGF were significantly higher than in all other groups. Granulocyte infiltration was reduced in both treatment groups, as well as reduced oedema formation. These results showed that VEGF released from fibrin had a positive effect on early I-R outcome in a mouse model, possibly via VEGFR-2. Copyright © 2016 John Wiley & Sons, Ltd.

Protective Effect of Platelet Rich Plasma on Experimental Ischemia/Reperfusion Injury in Rat Ovary

BACKGROUND/AIMS

Ovarian torsion is a common cause of local ischemic damage, reduced follicular activity and infertility. Platelet-rich plasma (PRP) contains growth factors with demonstrated cytoprotective properties; so we evaluated PRP efficacy in a rat ischemia/reperfusion (I/R) model.

METHODS

Sixty adult female Sprague-Dawley albino rats were randomly assigned to 6 groups of 8 animals each: Sham, Ischemia, I/R, Sham + PRP, I + PRP and I/R + PRP; and the remaining 12 used to prepare PRP. Ischemia groups were subjected to bilateral adnexal torsion for 3 h, while I/R and I/R + PRP groups received subsequent detorsion for 3 h. Intraperitoneal PRP was administered 30 min prior to ischemia (Ischemia + PRP) or reperfusion (I/R + PRP).

RESULTS

Total oxidant status (TOS), oxidative stress index (OSI) and total ovarian histopathological scores were higher in Ischemia and I/R groups than in the Sham group (p < 0.05). PRP decreased mean TOS, OSI and histopathological scores in I + PRP and I/R + PRP groups compared to the corresponding Ischemia and I/R groups (p < 0.001). There was a strong correlation between total histopathological score and OSI (r = 0.877, p < 0.001). Peritoneal vascular endothelial growth factor was significantly higher in PRP-treated groups than corresponding untreated groups (p < 0.05).

CONCLUSION

PRP is effective for the prevention of ischemia and reperfusion damage in rat ovary.

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.

Potential novel biomarkers for diabetic testicular damage in streptozotocin-induced diabetic rats: nerve growth factor Beta and vascular endothelial growth factor

Background. It is well known that diabetes mellitus may cause testicular damage. Vascular endothelial growth factor (VEGF) and nerve growth factor beta (NGF-β) are important neurotrophic factors for male reproductive system. Objective. We aimed to investigate the correlation between testicular damage and testicular VEGF and NGF-β levels in diabetic rats. Methods. Diabetes was induced by streptozotocin (STZ, 45 mg/kg/i.p.) in adult rats. Five weeks later testicular tissue was removed; testicular VEGF and NGF-β levels were measured by ELISA. Testicular damage was detected by using hematoxylin and eosin staining and periodic acid-Schiff staining, and apoptosis was identified by terminal-deoxynucleotidyl-transferase-mediated dUTP nick end labeling (TUNEL). Seminiferous tubular sperm formation was evaluated using Johnsen's score. Results. In diabetic rats, seminiferous tubule diameter was found to be decreased; basement membrane was found to be thickened in seminiferous tubules and degenerated germ cells. Additionally, TUNEL-positive cells were increased in number of VEGF+ cells and levels of VEGF and NGF-β were decreased in diabetic testes. Correlation between VEGF and NGF-β levels was strong. Conclusion. These results suggest that the decrease of VEGF and NGF-β levels is associated with the increase of the apoptosis and testicular damage in diabetic rats. Testis VEGF and NGF-β levels could be potential novel biomarkers for diabetes induced testicular damage.

The protective effect of Cold-inducible RNA-binding protein (CIRP) on testicular torsion/detorsion: an experimental study in mice

PURPOSE

To evaluate the expression of Cold-inducible RNA-binding protein (CIRP) in torsion/detorsion of the testes in different phases and demonstrate the protective effect of CIRP on testicular injury after torsion/detorsion (T/D) in an experimental mouse model.

METHODS

Twenty-four male BALB/c mice were divided randomly into 8 groups: normal control group (N), sham-operated group (S), torsion 2 h group (T2h), torsion/detorsion 12 h group (T/D12h), and T/D24h, T/D48h, T/D72h, and T/D96h groups. The testes were examined for the expression levels of CIRP. Another 32 male BALB/c mice were divided randomly in to 4 groups: normal control group (N), T/D group, T/D+pcDNA3.1 group, and T/D + pcDNA3.1-CIRP group. The plasmids were transfected into testes with in vivo-jetPEI. After 3 days, morphological changes, mean seminiferous tubule diameter (MSTD), and the number of the germ cell layers were observed. Superoxide dismutase (SOD) activity, the levels of malondialdehyde (MDA), and Bcl-2/Bax ratios were studied in the different groups.

RESULTS

Compared with the N and S groups, the expression of CIRP in the T2h group was down-regulated. In T/D groups, the levels of CIRP were reduced in a time dependent manner. Compared to T/D and T/D+pcDNA3.1 group, the MSTD, number of the germ cell layers, SOD activity, and Bcl-2/Bax ratio increased in T/D + pcDNA3.1-CIRP group, while the level of MDA decreased.

CONCLUSIONS

The results of our study have shown that down-regulated CIRP is involved in testicular injury after testicular torsion/detorsion. Up-regulation of the expression of CIRP may reduce the damage caused by torsion/detorsion, possibly by preventing germ cell oxidative stress and apoptosis.

The effects of α-lipoic acid against testicular ischemia-reperfusion injury in Rats

Testicular torsion is one of the urologic emergencies occurring frequently in neonatal and adolescent period. Testis is sensitive to ischemia-reperfusion injury, and, therefore, ischemia and consecutive reperfusion cause an enhanced formation of reactive oxygen species that result in testicular cell damage and apoptosis. α-lipoic acid is a free radical scavenger and a biological antioxidant. It is widely used in the prevention of oxidative stress and cellular damage. We aimed to investigate the protective effect of α-lipoic acid on testicular damage in rats subjected to testicular ischemia-reperfusion injury. 35 rats were randomly divided into 5 groups: control, sham operated, ischemia, ischemia-reperfusion, and ischemia-reperfusion +lipoic acid groups, 2 h torsion and 2 h detorsion of the testis were performed. Testicular cell damage was examined by H-E staining. TUNEL and active caspase-3 immunostaining were used to detect germ cell apoptosis. GPx , SOD activity, and MDA levels were evaluated. Histological evaluation showed that α-lipoic acid pretreatment reduced testicular cell damage and decreased TUNEL and caspase-3-positive cells. Additionally, α-lipoic acid administration decreased the GPx and SOD activity and increased the MDA levels. The present results suggest that LA is a potentially beneficial agent in protecting testicular I/R in rats.

Beneficial effects of (-)-epigallocatechin gallate on ischemia-reperfusion testicular injury in rats

BACKGROUND/PURPOSE

The purpose of the study was to determine the effect of (-)-epigallocatechin gallate (EGCG) on testicular ischemia-reperfusion injury in rats.

METHODS

Forty male Wistar rats were assigned to 5 groups. A sham operation was performed on the animals in group 1. In group 2, after 4 hours of unilateral testicular ischemia, 4 hours of testicular reperfusion was performed with EGCG administered 1 hour before reperfusion. In group 3, the same surgical procedure as in group 2 was performed, but without EGCG. Serum superoxide dismutase activity, creatine kinase, and lactate dehydrogenase were then measured in blood samples from groups 1 to 3. In group 4, after 4 hours of unilateral testicular ischemia, testicular reperfusion was performed. In group 5, the same procedure as in group 4 was performed, but with EGCG administered 1 hour before reperfusion. For groups 4 and 5, bilateral orchiectomy was performed for histologic examination 4 weeks after reperfusion was started.

RESULTS

Serum superoxide dismutase activity was significantly higher in group 2 than in group 3. The ratios of bilateral testicular weight, mean seminiferous tubule diameter, and germinal epithelial cell thickness were significantly higher in group 5 than in group 4.

CONCLUSIONS

Therapy with EGCG before reperfusion might exert protective effects via antioxidant activities in a rat experimental model of testicular ischemia-reperfusion injury.

Effects of polydeoxyribonucleotide on the histological damage and the altered spermatogenesis induced by testicular ischaemia and reperfusion in rats

The effects of polydeoxyribonucleotide (PDRN), an agonist of the A2A adenosine receptors which when activated positively influences sperm activity, were tested in an experimental testicular ischaemia/reperfusion injury model. Anaesthetized male Sprague-Dawley rats were subjected to testicular torsion-induced ischaemia, followed by reperfusion (TI/R). Immediately after detorsion, randomized animals, including SHAM, received intraperitoneal injections of: (i) vehicle (1 mL/kg 0.9% NaCl solution); (ii) PDRN (8 mg/kg); (iii) DMPX (3,7-dimethyl-1-propargilxanthine, 0.1 mg/kg); or (iv) PDRN (8 mg/kg) + DMPX (0.1 mg/kg). Animals were euthanized at 1, 7 and 30 days following reperfusion. Vascular endothelial growth factor (VEGF) expression is normally associated with adenosine A2A receptor stimulation. After treatment, VEGF mRNA/protein expression quantified by qPCR and Western blot, vascular endothelial growth factor receptor-1 (VEGFR1) and endothelial nitric oxide synthase (eNOS) mRNA measured by qPCR, VEGF and VEGFR1 assessed using immunohistochemical methods, histological staining and spermatogenic activity were all analysed. Testis ischaemia-reperfusion (TI/R) injury caused increases in VEGF mRNA and protein, VEGFR1 and eNOS mRNA, histological damage and reduced spermatogenic activity. Immunostaining showed a lower expression of VEGF in germinal epithelial cells and a strong expression of VEGFR1 in Leydig cells after TI/R. PDRN administration increased significantly VEGF message/protein, VEGFR1 and eNOS message, decreased histological damage and ameliorated spermatogenic activity. PDRN might be useful in the management of testicular torsion.

Effects of vardenafil on testicular torsion/detorsion damage: an experimental study in pigs

PURPOSE

To investigate the effects of vardenafil HCl on testicular germ cell apoptosis and the expressions of iNOS and eNOS within the bilateral testes after unilateral torsion/detorsion (T/D) in a pig model.

METHODS

12 male pigs weighing 50-55 kg were divided randomly into three groups (n = 4). Sham operation and T/D was performed in groups 1 and 2, respectively. Group 3 underwent T/D and received vardenafil (0.4 mg/kg) orally 45 min before detorsion. The testes were left in torsion for 2 h. In all groups, both testes were removed 8 h after the operation for histopathological analysis.

RESULTS

Except for group 1, the histopathologic parameters of the ipsilateral testes were higher than in the contralateral testes, and this difference was statistically significant (p < 0.05). Testicular ischemia/reperfusion (I/R) (group 2) resulted in marked increases in germ cell apoptosis, iNOS and eNOS in the ischemic testes compared to the sham-operated group. The pigs treated with vardenafil (group 3) also showed significantly increased apoptotic cells, iNOS and eNOS levels compared to the sham-operated group.

CONCLUSIONS

The results suggest that vardenafil HCl worsened histopathological changes related to oxidative stress in testicular injury and had no protective effect on testicular I/R injury in pigs.

The effects of N-acetylcysteine on testicular damage in experimental testicular ischemia/reperfusion injury

PURPOSE

The aim of this study to evaluate the effects of N-acetylcysteine (NAC) on testicular damage in a rat testicular ischemia-reperfusion (I/R) injury model.

METHODS

Thirty male Wistar albino rats were divided into five groups. Group 1: sham control, Group 2: torsion (T), Group 3: torsion/detorsion (T/D), Group 4: the early NAC treatment plus T/D, 20 mg/kg of NAC was given intravenously 60 min before detorsion; Group 5: the late NAC treatment plus T/D, 20 mg/kg of NAC was given intravenously 5 min before detorsion. After torsion (2 h) and detorsion (2 h), bilateral orchiectomies were performed to determine the tissue levels of malondialdehyde (MDA) or more exactly thiobarbituric acid reactive substance (TBARS), myeloperoxidase activity and histopathological changes.

RESULTS

The most significant increase in the mean TBARS level and decrease in the mean seminiferous tubular diameter, germinal epithelial cell thickness values in bilateral testes were observed in T/D group rather than other groups. TBARS levels of early NAC treatment group were significantly lowered and histological parameters of spermatogenesis were significantly improved in bilateral testes when compared with T and T/D groups.

CONCLUSION

Our results suggest that the early administration of NAC may have a protective effect in the rat experimental testicular T/D models.

Experimental ischaemia-reperfusion injury induces vascular endothelial growth factor expression in the rat testis

Testicular torsion causes ischaemia-reperfusion (I-R) injury of testis and might lead to male infertility. Its injury initiates a pathophysiological cascade, including an activation of inflammatory cytokines and generation of nitric oxide and other reactive oxygen species. Vascular endothelial growth factor (VEGF) mediates angiogenesis and promotes endothelial cell survival. The aim of our study was to investigate the time course expression of VEGF, VEGF-receptor (R)1, VEGF-R2, nitric oxide synthases (NOS) in experimental I-R injury of rat testis. In torsion side testis, the expression of VEGF protein and mRNA significantly increased in a time-dependent manner (P < 0.001 and P < 0.001, respectively). Although the expression of VEGF-R1 mRNA was increased in a similar way (P < 0.001), VEGF-R2 mRNA expression was not detected. In immunohistochemistry, the increase in VEGF protein staining was observed in testicular vascular endothelial cells and germ cells at 24 h after reperfusion. Significant activation of inducible NOS and endothelial NOS was investigated at 12 and 24 h after reperfusion (P < 0.01 and P < 0.001, respectively). This is the first report to show the time course expression of VEGF in experimental I-R rat testis.

Protective effect of trapidil on long-term histologic damage in a rat model of testicular ischemia-reperfusion injury

OBJECTIVES

Trapidil is an antianginal compound with a broad spectrum of pharmacological activities. In recent years, it has been used successfully to decrease ischemia-reperfusion injury in several organ systems. We evaluated the effect of trapidil on the long-term histologic damage in testicular ischemia-reperfusion injury.

METHODS

Adult male Wistar rats were divided into three groups of six rats each. One group underwent 2 h of testicular torsion; one received pretreatment with trapidil before detorsion; and one group underwent sham operation. All rats underwent bilateral orchiectomy 60 days after the experiment. The mean seminiferous tubular diameter, germinal epithelial cell thickness, and mean testicular biopsy score were determined by histological examination of each testis.

RESULTS

Testicular torsion-detorsion caused a significant decrease in the mean seminiferous tubular diameter, germinal epithelial cell thickness, and mean testicular biopsy score in the ipsilateral testes, but not in the contralateral testes. The animals treated with trapidil had a significant increase in these histological parameters as compared to the torsion-detorsion group.

CONCLUSION

Trapidil administration before reperfusion may have the potential to decrease the long-term histologic damage that occurs after experimental testicular torsion. Trapidil is used as an antianginal drug and additional clinical studies are required to elucidate the protective role of trapidil in patients with testicular torsion.

Role of cAMP-responsive element modulator-τ (CREMτ) in ipsilateral testicular injury after unilateral testicular torsion-detorsion

OBJECTIVE

To investigate the role of cAMP-responsive element modulator-tau (CREMtau), an essential transcription factor for spermatogenesis, in ipsilateral testicular injury after unilateral testicular torsion-detorsion.

DESIGN

Controlled experimental study using rats.

SETTING

Research laboratory.

ANIMAL(S)

Twenty adult male Sprague-Dawley rats.

INTERVENTION(S)

Ten rats in the control group underwent a sham operation of the left testes. Ten rats in the torsion-detorsion group received 1 hour of left testicular torsion. Orchiectomy was performed on all rats 3 months after detorsion.

MAIN OUTCOME MEASURE(S)

Testicular spermatogenesis was evaluated by measuring testicular weight, mean seminiferous tubular diameter, number of germ cell layers, and mean testicular biopsy score. The expressions of CREMtau mRNA and protein in testes were detected by reverse transcription-polymerase chain reaction and Western blot, respectively.

RESULT(S)

Unilateral testicular torsion-detorsion caused significant spermatogenic damage in the ipsilateral testes, including reductions in testicular weight, mean seminiferous tubular diameter, number of germ cell layers, and mean testicular biopsy score. In ipsilateral testes with spermatogenic damage, the expressions of CREMtau mRNA and protein were also significantly reduced.

CONCLUSION(S)

Reduction in testicular CREMtau expression may be one of the mechanisms responsible for impairment of spermatogenesis in ipsilateral testes after unilateral testicular torsion-detorsion.

Antiapoptotic effects of dehydroepiandrosterone on testicular torsion/detorsion in rats

In the present study, we aimed to evaluate the effects of dehydroepiandrosterone (DHEA) on apoptosis of testicular germ cells after repair of testicular torsion in rats. Twenty-four adult male Sprague-Dawley rats were randomly divided into four groups, with six rats in each group: sham operation, torsion/detorsion (T/D), T/D + vehicle, and T/D + DHEA. Three hours before detorsion, 50 mg kg(-1) DHEA was given intraperitoneally to T/D + DHEA group. In all groups, bilateral orchiectomies were performed and both testicles were histologically examined, with apoptosis detected using the in situ DNA fragmentation [terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL)] system, with morphological damage detected using a four-level grading scale in each specimen. The testes of the sham group showed a normal histology. In T/D and T/D + vehicle groups, apoptotic spermatogonia and spermatocyte number were significantly higher than in the sham group (P < 0.01 for all). The T/D + DHEA group showed a reduction in apoptotic spermatocyte and spermatogonia number in seminiferous epithelia compared with T/D group (P < 0.01 for both). Apoptotic cell number of contralateral testes did not reveal any significant differences among these groups (P > 0.05). Specimens from T/D and T/D + vehicle had a significantly greater histological injury than sham and T/D + DHEA groups in the ipsilateral testes (P < 0.01 for both). Therefore, the results suggest that DHEA may be a protective agent for preventing apoptosis caused by testicular torsion.

Protective effect of erythropoietin pretreatment in testicular ischemia-reperfusion injury in rats

BACKGROUND/PURPOSE

This study was designed to investigate the effects of recombinant erythropoietin (EPO), a hormone widely used for treatment of uremic anemia, in rats subjected to testicular ischemia and reperfusion (I/R).

METHODS

Thirty-five male rats were divided into the following: control, sham operated, ischemia (I), I/R, and I/R + EPO groups. In the I group, 2 hours of left unilateral testicular torsion were performed, and in the I/R and I/R + EPO groups, an additional 2 hours of testicular detorsions were performed. The I/R + EPO group was pretreated intraperitoneally with EPO (500 IU/kg) before reperfusion. Testicular tissue samples were examined for biochemical and histopathologic parameters. Apoptotic cells in all testes were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling technique and caspase 3 immunohistochemistry.

RESULTS

At histopathologic examination, ischemic changes in primary spermatocytes were noted in all torted testes. Cellular damage and apoptosis were more severe in ischemic groups than the EPO-pretreated group. There were statistically significant differences in tissue biochemical parameters in the I and I/R groups compared with the I/R + EPO group.

CONCLUSIONS

The results of the present study suggest that EPO exerts protective effects against I/R injury via the modulation of free radical scavenger's activities, which decreases lipid peroxidation levels and attenuation of apoptosis.

Curcumin attenuates ischemia-reperfusion injury in rat testis

OBJECTIVE

To evaluate the effect of curcumin, a potent antioxidant, on testicular ischemia-reperfusion injury caused by overgeneration of reactive oxygen species (ROS) after testicular torsion-detorsion.

DESIGN

Controlled experimental study using rats.

SETTING

Research laboratory.

ANIMAL(S)

Sixty adult male Sprague-Dawley rats.

INTERVENTION(S)

Rats in the control group underwent a sham operation of the left testis. In the torsion-detorsion group, the left testis was rotated 720 degrees for 2 hours. Rats in treatment group received the same surgical procedure as the torsion-detorsion group, but curcumin was administered IV at repair of testicular torsion.

MAIN OUTCOME MEASURE(S)

Testicular activity of xanthine oxidase, which catalyzes production of ROS; malondialdehyde level (an indicator of ROS content); protein expression level of heme oxygenase-1, which catalyzes antioxidant generation; and spermatogenesis.

RESULT(S)

Unilateral testicular torsion-detorsion caused significant increases in xanthine oxidase activity, malondialdehyde level, and heme oxygenase-1 protein expression level and caused a significant decrease in testicular spermatogenesis in ipsilateral testes. The rats treated with curcumin had significant decreases in xanthine oxidase activity and malondialdehyde level and had significant increases in heme oxygenase-1 protein expression level and testicular spermatogenesis in ipsilateral testes, compared with the torsion-detorsion group.

CONCLUSION(S)

The curcumin exerts a protective effect on testicular ischemia-reperfusion injury.

The protective effects of trimetazidine on testicular ischemia and reperfusion injury in rats

This study was designed to investigate the protective effect of trimetazidine [TMZ; 1-(2, 3, 4-trimethhoxibenzyl)-piperazine dihydrochloride], as an antioxidant agent, on torsion-detorsion-induced biochemical and histopathological changes in experimental testicular ischemia/reperfusion injury in rats. Twenty-seven male Wistar rats weighing 180-220 g were divided into five groups: control (C, n = 4), sham-operated (S, n = 4), ischemia (I, n = 6), ischemia-reperfusion (I/R, n = 6) and ischemia-reperfusion + trimetazidine (I/R + TMZ; n = 7). Control rats were used for basal normal values. In group I, 2 h torsion of the left testis was performed. In I/R and I/R + TMZ groups, following 2 h of torsion, 4 h detorsion of the testis was performed. In ischemia and I/R groups, physiologic saline was administered orally for 7 days, and the rats in I/R + TMZ group were pretreated orally with 5 mg/kg day TMZ for 7 days before inducing ischemia. At the end of each experiment, ipsilateral orchiectomies were performed for the tissue levels of malondialdehyde (MDA), glutathione peroxidase (GPx) enzyme activities and histopathological examinations in all groups. MDA levels were significantly reduced and GPx enzyme activities were significantly increased in testes in I/R+TMZ pretreated group compared to group I and I/R. The mean seminiferous tubular diameter (MSTD) and Johnsen's score were significantly better in I/R+TMZ group than groups I and I/R. Pretreatment with TMZ decreased germ cell apoptosis and caspase-3 expression in the ischemic testis. The present results show that TMZ has a protective activity in the testicular injury caused by I/R, and provide the first evidence of the role of TMZ for the prevention of I/R-induced testicular injury.

Dehydroepiandrosterone treatment attenuates reperfusion injury after testicular torsion and detorsion in rats

PURPOSE

We aimed to evaluate the effects of dehydroepiandrosterone (DHEA) on antioxidant enzyme activities, lipid peroxidation, and histopathologic changes in both testes after unilateral testicular torsion and detorsion.

METHODS

Twenty-four adult male Sprague-Dawley rats were randomly divided into 4 groups (n = 6 for each group): sham operation, torsion/detorsion (T/D), T/D + vehicle, and T/D + DHEA. Three hours before detorsion, 50 mg/kg DHEA was given intraperitoneally to the T/D + DHEA group. Testicular ischemia was achieved by twisting the left testis 720 degrees clockwise for 3 hours, and reperfusion was allowed for 24 hours after detorsion. In all groups, bilateral orchiectomies to determine the testicular tissue catalase (CAT) and superoxide dismutase activities and malondialdehyde (MDA) levels and histopathologic examination were performed.

RESULTS

Compared with those from the sham group, CAT activities in the ipsilateral testis obtained from the T/D group were significantly lower and MDA levels were significantly higher (P < .05 for all). Administration of DHEA prevented increases in MDA levels and decreases in CAT and superoxide dismutase activities when compared to the T/D group. Specimens from the T/D and the T/D + vehicle groups had a significantly greater histologic injury than the specimens from the sham and the T/D + DHEA groups had (P < .01 for both).

CONCLUSIONS

The results suggest that DHEA may be a protective agent for preventing biochemical and histopathologic changes related to oxidative stress in testicular injury caused by testis torsion.