An experimental study on effects of pyrrolidine dithiocarbamate on ischemia-reperfusion injury in testis

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 torsion in vivo models: Mechanisms and treatments

BACKGROUND

Testicular torsion is a condition in which a testis rotates around its longitudinal axis and twists the spermatic cord. This in turn results in a significant decrease in blood flow and perfusion of testicular tissue. During Testicular torsion, the testicular tissue is affected by ischemia, heat stress, hypoxia, and oxidative and nitrosative stress. The testicular torsion should be considered an emergency condition and surgical intervention (testicular detorsion ) as the sole treatment option in viable cases involves counter-rotation on twisted testes associated, when possible, to orchipexy, in order to avoid recurrence. Possible testicular detorsion side-effects occur due to reperfusion and endothelial cells injury, microcirculation disturbances, and intense germ cells loss.

OBJECTIVES

To discuss testicular torsion surgery-based methods, different time frames for testicular torsion induction, and the associated pathophysiology by emphasizing cellular and molecular events as well as different therapeutic agent applications for testicular torsion.

MATERIALS AND METHODS

We reviewed all original research and epidemiological papers related to testicular torsion condition.

RESULTS

Testicular torsion causes germ cell necrosis, arrested spermatogenesis, and diminished testosterone levels, with consequent infertility. Among different involved pathophysiological impacts, testicular torsion/detorsion-induced ischemia seems to play the key role by leading the tissue toward other series of events in testis. Numerous studies have used adjuvant antioxidants, calcium channel blockers, anti-inflammatory agents, or vasodilating agents in order to decrease these effects.

DISCUSSION AND CONCLUSION

To the best of our knowledge, no previously conducted study examined therapeutical agents' beneficial effects post clinical I/R condition in humans. Different agents targeting different pathophysiological conditions were used to ameliorate the ischemia/reperfusion-induced condition in animal models, however, none of the administrated agents were tested in human cases. Although considering testicular detorsion surgery is still the golden method to reverse the testicular torsion condition and the surgical approach is undeniable, the evaluated agents with beneficial effects, need to be investigated furthermore in clinical conditions. Thus, furthermore clinical studies and case reports are required to approve the animal models proposed agents' beneficial impacts.

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

BACKGROUND

Testicular torsion is a urological emergency that requires urgent surgical intervention which results in testicular loss if not diagnosed and treated in a timely fashion. Ischemic tissue damage with oxygen deficiency, which starts with the decrease in blood flow to the tissue, continues to increase with the reoxygenation of the damaged tissues as soon as reperfusion is achieved. In various studies, osthole has also been shown to reduce cerebral, spinal cord, intestinal, renal, and myocardial ischemia/perfusion (I/R) damage. The aim of this study is to examine the effects of osthole on testicular I/R injury.

METHODS

28 Wistar-albino rats were randomly divided into four experimental groups (n=7). Group 1 was the sham operation group. In Group 2 (I/R), 3-h ischemia was created by rotating the testis 720° clockwise, followed by 3 h of reperfusion. In Group 3 (I/R + single dose of Osthole), 20 mg/kg ostol was administered intraperitoneally half an hour before detorsion after 3 h of torsion. The testis was detorsioned. Three h of detorsion was applied. In Group 4 (I/R + twice doses of Osthole), 20 mg/kg ostol was administered intraperitoneally half an hour before detorsion, followed by 3-h torsion. The testis was released and detorsioned. Half an hour after the detorsion, an intraperitoneal dose of 20 mg/kg osthole was administered again. Detorsion was done for 3 h. All rats were sacrificed after 6 h and right orchiectomy was performed for blood for biochemical analysis and histopathological sample.

RESULTS

Glutathion, nuclear respiratory factor 2, Superoxide dismutase, and 8-hydroxydeoxyguanosine levels were decreased in I/R rats, while interleukin-6, malondialdehyde, and myeloperoxidase levels were increased. While caspase 3, caspase 8, caspase 9, and TUNEL showed moderate immunopositive tissues immunohistochemically in rats with I/R damage, mild immunopositive tissues were detected in Group 3 and Group 4. In the histochemical examination, degenerative tubule structure and separation of epithelial cells were observed in I/R rats, while partially healed testicular tissue was detected in Group 3 and Group 4.

CONCLUSION

In our study, we observed that osthole reduced oxidative damage, suppressed the inflammatory process, prevented apoptosis, and reduced cell damage. We think that with repeated doses, cellular damage would gradually decline.

Therapeutic Effect of Stem Cells on Male Infertility in a Rat Model: Histological, Molecular, Biochemical, and Functional Study

Methotrexate (MTX) is a folic acid antagonist, widely used as a chemotherapeutic and immunosuppressive drug, but it is toxic to reproductive systems. In recent years, the era of stem cell applications becomes a promising point as a possible therapeutic agent in male infertility. This study is aimed at evaluating the therapeutic effects of stem cells at histological, molecular, biochemical, and functional levels in a methotrexate-induced testicular damage model. Material and Methods. Thirty rats were divided randomly into three groups (ten rats each): group 1 (control): animals received an intraperitoneal injection of 2 ml phosphate-buffered saline per week for 4 weeks, group 2 (MTX-treated group): animals were intraperitoneally injected with methotrexate (8 mg/kg) once weekly for 4 weeks, and group 3 (ADMSC-treated group): methotrexate-treated animals received a single dose of 1 × 10⁶ stem cells/rat at the 5th week. At the 8th week, blood samples were collected for hormonal analysis; then, animals were sacrificed. The testes were dissected; the right testis was stained with hematoxylin and eosin. Random sections were taken from group 3 and examined with a fluorescent microscope. The left testis was divided into two specimens: the first was used for an electron microscope and the second was homogenized for molecular and biochemical assessments. Results. Group 2 showed significant histological changes, decreased free testosterone level, decrease in stem cell factor expression, and dysfunction of the oxidation state. The results revealed significant improvement of these parameters. Conclusion. Transplantation of adipose tissue-derived stem cells (ADMSCs) can improve the testicular damage histologically and functionally in a rat model.

Carvacrol treatment opens Kir6.2 ATP-dependent potassium channels and prevents apoptosis on rat testis following ischemia-reperfusion injury model

Testicular torsion is a urological problem that causes subfertility and testicular damage in males. Testis torsion and detorsion lead to ischemia–reperfusion (IR) injury in the testis. Testicular IR injury causes the increase of reactive oxygen species (ROS), oxidative stress (OS) and germ cell-specific apoptosis. In this study, we aimed to investigate whether Carvacrol has a protective effect on testicular IR injury and its effects on Kir6.2 channels, which is a member of adenosine triphosphate (ATP)-dependent potassium channels. In the study, 2–4 months old 36 albino Wistar rats were used. For experimental testicular IR model, the left testis was rotated counterclockwise at 720° for two hours, and after two hours following torsion, detorsion was performed. Carvacrol was dissolved in 5% Dimethyl Sulfoxide (DMSO) at a dose of 73 mg/kg and half an hour before detorsion, 0.2 mL was administered intraperitoneally. In testicular tissues, caspase 3 and Kir6.2 immunoexpressions were examined. Serum malondialdehyde (MDA) and testosterone levels were measured. Apoptotic cells and serum MDA levels were significantly decreased and Kir6.2 activation was significantly increased in Carvacrol-administrated IR group. As a result of our study, Carvacrol may activates Kir6.2 channels and inhibits apoptosis and may have a protective effect on testicular IR injury.

Dose dependent effect of cilostazol in induced testicular ischemia reperfusion via modulation of HIF/VEGF and cAMP/SIRT1 pathways

Twisting of the spermatic cord is a common dangerous health problem that may be accompanied with testicular necrosis and infertility. Cilostazol (CLZ) is a selective phosphodiesterase (PDE) 3A inhibitor used for treatment of intermittent claudication. It has a great role in myocardial, spinal cord and hepatic ischaemia/reperfusion. However, till now, there are no researches evaluating its role in testicular ischaemia/reperfusion (TIR). The current work studies its capability to improve TIR induced injury with more concentration on the mechanisms involved in such effect. Four groups of animals were included: sham, TIR induced group, TIR plus CLZ low dose (10 mg/kg), TIR plus CLZ high dose (30 mg/kg). Our results proved that TIR had significant decrease of the serum ELISA of testosterone, marked disturbances in oxidative stress evaluated parameters as malondialdehyde (MDA), reduced glutathione (GSH), total antioxidant capacity (TAC), ELISA measurement of tumor necrosis factor alpha (TNFα) and interleukin 1 beta (IL1β) inflammatory mediators, apoptotic marker (caspase3) using western blotting, immunohistochemistry of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF). TIR reduced the protective agents as cyclic adenosine monophosphate (cAMP) and sirtuin-1 (SIRT1) by ELISA method with marked germinal cell apoptosis. The biochemical results were confirmed by the histopathological findings that showed marked decrease in both Johnsen's score and Cosentino's score. However, treatment with CLZ significantly reversed the profound TIR damaging effects, on the basis of its anti-inflammatory, anti-oxidant, and anti-apoptotic activities with recuperation of the testicular vascularity. Modulation of HIF/VEGF and cAMP/SIRT1 pathways showed a great role in mediating such effect.

Protective effect of pyrrolidine dithiocarbamate against methotrexate-induced testicular damage

The aim of the study was to investigate the protective effect of pyrrolidine dithiocarbamate (PDTC) against methotrexate (MTX)-induced testicular damage in rats. Forty Wistar albino male rats were divided into equally four groups: Control group (saline solution, IP), PDTC group (100 mg/kg PDTC,IP, 10 days), MTX group (20 mg/kg MTX, IP, single dose, on the 6th day) and MTX + PDTC group (100 mg/kg PDTC, IP, 10 days and 20 mg/kg MTX, IP, single dose, on the 6th day). After 10 days, testicular tissues were excised for morphometric, histological and immunohistochemical evaluations. Serum testosterone, follicle stimulating hormone (FSH), luteinizing hormone (LH) and prokineticin 2 (PK2) levels were determined. Body and testicular weights were measured. Testicular damage was assessed by histological evaluation. Nuclear factor kappa B (NFkB), nuclear factor erythroid 2 related factor 2 (Nrf2) and PK2 immunoreactivities were evaluated by HSCORE. Body and testicular weights, serum FSH, LH, testosterone levels, seminiferous tubule diameter and germinal epithelial thickness were significantly decreased in the MTX group. However, serum PK2 level, histologically damaged seminiferous tubules and interstitial field width were significantly increased. Additionally, there was an increase in NFkB and PK2 immunoreactivity, whereas there was a significant decrease in Nrf2 immunoreactivity. PDTC significantly improved hormonal, morphometric, histological and immunohistochemical findings. Taken together, we conclude that PDTC may reduce MTX-induced testicular damage via NFkB, Nrf2 and PK2 signaling pathways.

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.

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.