The protective effect of darbepoetin alfa on experimental testicular torsion and detorsion 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.

Erythropoitein Increases In Vitro Motility and Vitality of Human Spermatozoa

BACKGROUND/AIM

Erythropoietin and its receptor are expressed in the male reproductive system. Initial studies have shown that erythropoietin affects the motility of spermatozoa. The aim of the present study was to investigate the in vitro effect of erythropoietin in the motility and vitality of human spermatozoa.

MATERIALS AND METHODS

Forty-three semen samples, obtained after 2-4 days of abstinence from sex, were analyzed and processed using density gradient centrifugation. Aliquots containing one million of spermatozoa were treated with either erythropoietin, at concentrations of 10 and 100 mIU/μl or standard culture medium for one hour.

RESULTS

Progressive motility and vitality of spermatozoa significantly increased following treatment with erythropoietin. The effect was not dose-dependent.

CONCLUSION

The supplementation of culture medium with erythropoietin improves sperm processing in terms of vitality and motility. Future research should focus on the effects of erythropoietin on sperm capacitation as well as on the signal transduction pathways activated by erythropoietin and its receptor in spermatozoa.

The theoretical method and clinical application of testicular torsion

INTRODUCTION

This study aims to explore the theoretical method and clinical application of manipulation reduction for testicular torsion.

METHODS

A total of 28 patients with testicular torsion were recruited from the Emergency Surgery Department of Beijing Children's Hospital affiliated to Capital Medical University from July 2016 to July 2018. Among these patients, 22 patients (age: 10.80 ± 3.50 years old) were treated with manual reduction using the elastic retraction method and push-and-turn method. Observation indexes included dramatically alleviated or completely disappeared pain without general anesthesia; the spermatic cord being smooth and unknotted; the restoration of the suffered testis to normal anatomical position under ultrasonography monitoring; blood flow signals increased in the affected testis and epididymis, which was regarded as the main sign of a successful reduction.

RESULTS

Among the 22 cases who received manual reduction, 19 patients were successfully treated (left side: n = 11, right side: n = 8) with a total success rate of 86.36%. The other three cases showed either incomplete (n = 2) or failed (n = 1) reposition. Among the 19 patients who were successfully treated by manual reduction, 2 of them did not undergo prophylactic orchiopexy, and no abnormalities were found during the follow-up.

CONCLUSION

The reduction of testicular torsion using the elastic retraction method and push-and-turn method may improve the success rate of the manual reduction of testicular torsion, especially for incomplete testicular torsion. Furthermore, manual reduction may help increase the rate of testicular salvage in a timely manner before emergency surgery. Hence, this skill should be extended to primary hospitals to reduce the possibility of testectomy caused by testicular torsion.

Erythropoietin and sildenafil protect against ischemia/reperfusion injury following testicular torsion in adult rats

Testicular torsion/detorsion causes severe tissue damage due to ischemia/reperfusion injury. The present study investigated the protective effect of erythropoietin and sildenafil against ischemia/reperfusion injury following unilateral testicular torsion/detorsion in adult rats. A total of 28 adult male rats were included, and were divided into the following groups: Group A (n=5), sham operated; groups B (n=5), C (n=5), D (n=5) and E (n=8), undergoing right testis torsion and detorsion after 90 min. Group B received no drug treatment. Rats in the groups C and D received low-dose (1,000 IU/kg) or high-dose (3,000 IU/kg) erythropoietin, while those in group E received sildenafil (0.7 mg/kg), through intraperitoneal injection after 60 min of torsion. The right testis was extracted 24 h after detorsion, and the tissue was subjected to histopathological examination and immunohistochemical assessment of cleaved caspase-3 expression. Histological alterations and the quality of spermatogenesis were scored according to the Cosentino and the Johnsen scoring systems, respectively. The results demonstrated normal testicular architecture in group A, while the other groups showed ischemic cellular damages, with the worst scores observed in group B. Groups D and E presented better scores compared with group C. Regarding the quality of spermatogenesis, the best scores were observed in group A, and the worst in group B. Groups C, D and E presented similar results, which were improved in comparison to group B, however, not compared to group A. Furthermore, cleaved caspase-3 levels were lower in groups A, D and E, with equal results observed. Group C had higher levels of cleaved caspase-3 compared with these groups, but lower than group B, which presented the highest cleaved caspase-3 levels. In conclusion, erythropoietin and sildenafil protect testis from ischemia/reperfusion injury by decreasing cellular damage and attenuating apoptosis.

Medical perspective in testicular ischemia-reperfusion injury

Testicular torsion or torsion of the spermatic cord is one of the most serious urological conditions. It causes testicular injury, which potentially leads to male subfertility. The turning of the spermatic cord and spermatic structures around themselves results in biochemical and histological changes; however, following testicular detorsion, tissues undergo reperfusion that causes more severe damage than that induced by ischemia. Since the primary causes of testicular damage are reactive oxygen species production, an increase in intra-mitochondrial calcium concentration and an increased rate of cellular apoptosis, different medications may potentially be effective. It seems that several medications, experimentally and sometimes clinically, serve an adjuvant role in the cellular damage that occurs following ischemia-reperfusion. Antioxidants, calcium channel blockers, phytotherapeutical medicinals, anaesthetics, hormones and platelet inhibitors may potentially create a solid basis for an adjuvant restoring therapy and ameliorate testicular function following torsion. The current study aimed to review the relevant literature and discuss the actions of a number of molecules that may protect the testes during ischemia/reperfusion injury.

Antioxidant and antiapoptotic effects of darbepoetin-α against traumatic brain injury in rats

INTRODUCTION

In this study, we tried to determine whether darbepoetin-α would protect the brain from oxidative stress and apoptosis in a rat traumatic brain injury model.

MATERIAL AND METHODS

The animals were randomized into four groups; group 1 (sham), group 2 (trauma), group 3 (darbepoetin α), group 4 (methylprednisolone). In the sham group only the skin incision was performed. In all the other groups, a moderate traumatic brain injury modelwas applied.

RESULTS

Following trauma both glutathione peroxidase, superoxide dismutase levels decreased (p < 0.001 for both); darbepoetin-α increased the activity of both antioxidant enzymes (p = 0.001 and p < 0.001 respectively). Trauma caused significant elevation in the nitric oxide synthetase and xanthine oxidase levels (p < 0.001 for both). Administration of darbepoetin-α significantly decreased the levels of nitric oxide synthetase and xanthine oxidase (p < 0.001 for both). Also, trauma caused significant elevation in the nitric oxide levels (p < 0.001); darbepoetin-α administration caused statistically significant reduction in the nitric oxide levels (p < 0.001). On the other hand, malondialdehyde levels were increased following trauma (p < 0.001), and darbepoetin α significantly reduced the malondialdehyde levels (p < 0.001). Due to the elevated apoptotic activity following the injury, caspase-3 activity increased significantly. Darbepoetin-α treatment significantly inhibited apoptosis by lowering the caspase-3 activity (p < 0.001). In the darbepoetin group, histopathological score was lower than the trauma group (p = 0.016).

CONCLUSIONS

In this study, darbepoetin-α was shown to be at least as effective as methylprednisolone in protecting brain from oxidative stress, lipid peroxidation and apoptosis.

Comparison of erythropoietin and sildenafil protective role against ischemia/reperfusion injury of the testis in adult rats

PURPOSE

Tissue damage in testicular torsion/detorsion is caused not only by the ischemia, but also by the ischemia/reperfusion injury after detorsion. Erythropoietin and sildenafil are considered to protect against ischemia/reperfusion injury. Here, we studied and compared their actions in testicular torsion/detorsion in adult rats.

METHODS

Twenty-two adult male Wistar Albino rats were divided into four groups. Rats in group A (n = 5) were sham operated. Rats in group B (n = 5), group C (n = 6) and group D (n = 6) underwent torsion of the right testis and detorsion after 90 min. No pharmaceutical intervention was performed in group B. Erythropoietin (1,000 IU/kg) and sildenafil (0.7 mg/kg) were injected intraperitoneally in groups C and D, respectively, after 60 min of torsion. All animals were killed 24 h after detorsion, and their right testis was extracted, placed into 10 % formalin solution and sent for histopathological examination. The histological changes in the testes were scored according to the four-point grading system proposed by Cosentino et al.

RESULTS

All rats in group A had normal testicular architecture (grade 1). The untreated group B had a mean grade of 3.81 (range 3.65-4). The treated groups C (mean grade 3.24; range 3.05-3.45) and D (2.69, range 2.4-2.9) presented statistically significant better results (lower grades) compared with the untreated group B. Group D had significantly better results (lower grades) than group C.

CONCLUSIONS

The intraperitoneal injection of erythropoietin and sildenafil protects against ischemia/reperfusion injury after testicular torsion and detorsion. Sildenafil may have a stronger action than erythropoietin at the doses used in this study.

The effect of erythropoietin on ischemia/reperfusion injury after testicular torsion/detorsion: a randomized experimental study

This study was conducted to investigate the protective effect of erythropoietin (EPO) on ischemia/reperfusion related changes after testicular torsion/detorsion. In a randomized experimental trial 30 male rats were randomly allocated into six equal groups of five rats each. Group I (orchiectomy for histopathologic examination), group II (sham operation), group III (torsion for 2 hours, and ischemia/detorsion for 24 hours, and orchiectomy); group IV (torsion for 2 hours, ischemia/detorsion for 24 hours with erythropoietin injection then orchiectomy), group V (torsion for 2 hours and detorsion and EPO injection and orchiectomy 1 week later, group VI (torsion for 2 hours/detorsion and orchiectomy 1 week later). Two groups (groups 4 and 5) received different protocols of erythropoietin administration after testicular torsion/distortion. other groups were not receiving erythropoietin. Johnsen's spermatogenesis scoring method and Cosentino's histologic staging method were used to assess main outcome measures of the study. After the experimentation, Johnsen's score in EPO Groups was statistically different from the score in some groups not receiving erythropoietin. Cosentino's score in EPO groups was statistically different from the score in all groups not receiving erythropoietin. Neovascularization, vascular necrosis, vascular congestion, edema, hemorrhage, and acute inflammation were observed in some groups. This study shows short-term protective efficacy of erythropoietin on rat testicular injury after ischemia/reperfusion.

Melanocortin 4 receptor activation protects against testicular ischemia-reperfusion injury by triggering the cholinergic antiinflammatory pathway

Melanocortins (MC) trigger a vagus nerve-mediated cholinergic-antiinflammatory pathway projecting to the testis. We tested whether pharmacological activation of brain MC receptors might protect the testis from the damage induced by ischemia-reperfusion. Adult male rats were subjected to 1-h testicular ischemia, followed by 24-h reperfusion [testicular ischemia-reperfusion (TI/R)]. Before TI/R, groups of animals were subjected to bilateral cervical vagotomy, or pretreated with the nicotinic acetylcholine receptor antagonist chlorisondamine or the selective MC(4) receptor antagonist HS024. Immediately after reperfusion, rats were ip treated with saline or the MC analog [Nle(4),D-Phe(7)]α-melanocyte-stimulating hormone (NDP-α-MSH) (340 μg/kg). We evaluated testicular IL-6 and TNF-α by Western blot analysis and organ damage by light microscopy. Some experimental groups were prepared for neural efferent activity recording along the vagus nerve starting 30 min after treatment with NDP-α-MSH or saline, and for a 30-min period. Additional groups of TI/R rats were treated for 30 d with saline, NDP-α-MSH, chlorisondamine plus NDP-α-MSH, or HS024 plus NDP-α-MSH to evaluate spermatogenesis, organ damage, and the apoptosis machinery. After a 24-h reperfusion, in TI/R saline-treated rats, there was an increase in IL-6 and TNF-α expression and a marked damage in both testes. NDP-α-MSH inhibited IL-6 and TNF-α expression, decreased histological damage, and increased neural efferent activity. Furthermore, NDP-α-MSH administration for 30 d greatly improved spermatogenesis, reduced organ damage, and inhibited apoptosis. All positive NDP-α-MSH effects were abrogated by vagotomy, chlorisondamine, or HS024. Our data suggest that selective MC(4) receptor agonists might be therapeutic candidates for the management of testicular torsion.

Gradual detorsion of torsioned rat testis attenuates ischemia reperfusion injury

AIM

This study was designed to investigate effect of gradual detorsion on testicular ischemia reperfusion injury.

MATERIALS AND METHODS

A total of 21 male rats were divided into 3 groups, each containing 7 rats. Torsion was created by rotating the left testis 720 degrees in a clockwise direction. Group 1 underwent sham operation. Group 2 (sudden detorsion) served as a torsion/detorsion group, receiving 2 hours torsion and 2 hours detorsion. In group 3, 360 degrees detorsion was done for 20 minutes after 720 degrees torsion for 2 hours. Then, testis was done full detorsion for 100 minutes. At the end of the experiments (fourth hour), left orchiectomy was performed to measure the tissue levels of malondialdehyde (MDA), superoxide dismutase, and glutathione peroxidase and to perform histologic examination in testes.

RESULTS

The MDA levels of testis tissues were significantly increased in the sudden detorsion group as compared with the sham group. We found decrease of the MDA level in gradual detorsion group, but it was not a statistically significant amount. Significant decrease was found in the superoxide dismutase and glutathione peroxidase activities in the sudden detorsion group as compared with the sham and gradual detorsion groups. Histologic examinations were in accordance with the testicular tissue MDA levels.

CONCLUSION

In the light of our biochemical and histopathologic findings, we can say that gradual detorsion has a trend to decrease the degree of testicular reperfusion injury in the rat torsion/detorsion model.

The protective effect of erythropoietin infusion on testicular torsion/detorsion: an experimental study

INTRODUCTION

The aim of the present study was to evaluate the effects of erythropoietin (EPO) on the histopathology of testes after unilateral testicular torsion and detorsion.

MATERIALS AND METHODS

Twenty-five male Sprague-Dawley rats weighing 120 g were used in this study. The rats were randomly divided into three groups, a sham group consisting of five rats and the other two groups consisting of ten rats. In group 1 (sham group), right orchiectomy with no additional intervention was performed. In group 2 (T/D group), torsion was created by rotating the testis 720 degrees in a clockwise direction for 4 h. After a 4-h torsion period, the right testis was detorted and replaced into the scrotum for 4 h. After the torsion, 0.5 cc 0.9% NaCl solution was injected once and three times in a week (total 12 doses). In group 3 (T/D + erythropoietin; EPO group), the same surgical procedure was done as in group 1, but EPO 1,000 IU/kg was injected just before the detorsion and three times in a week. At the end of each procedure, bilateral orchiectomies were performed for the histopathological examinations in all groups.

RESULTS

We examined the testes weight, vascularization of the region between the seminiferous tubules, percentage of necrotic seminipherous tubules, and maturation of spermatogenesis in terms of necrosis, sertoli cells, maturation arrest of spermatogenesis, hypospermatogenesis, and normal spermatogenesis of torsioned testis tissues with and without EPO treatment. Extremely significant differences in testicular weight were observed in group 1 compared to groups 2 and 3 (P < 0.001).

CONCLUSION

Administration of EPO significantly influenced the rescue of testicular function by preserving the intact seminiferous tubular morphology, lowering the percentage of necrotic seminipherous tubules, and significantly reducing histological damage (P < 0.05).

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.