Effect of angiotensin-converting enzyme inhibition and angiotensin II type 1 receptor blockade on apoptotic changes in contralateral testis following unilateral testicular torsion

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.

Combination Therapy with Enalapril and Paricalcitol Ameliorates Streptozotocin Diabetes-Induced Testicular Dysfunction in Rats via Mitigation of Inflammation, Apoptosis, and Oxidative Stress

BACKGROUND

As the impacts of diabetes-induced reproductive damage are now evident in young people, we are now in urgent need to devise new ways to protect and enhance the reproductive health of diabetic people. The present study aimed to evaluate the protective effects of enalapril (an ACE inhibitor) and paricalcitol (a vitamin D analog), individually or in combination, on streptozotocin (STZ)-diabetes-induced testicular dysfunction in rats and to identify the possible mechanisms for this protection.

MATERIAL AND METHODS

This study was carried out on 50 male Sprague-Dawley rats; 10 normal rats were allocated as a non-diabetic control group. A total of 40 rats developed diabetes after receiving a single dose of STZ; then, the diabetic rats were divided into four groups of equivalent numbers assigned as diabetic control, enalapril-treated, paricalcitol-treated, and combined enalapril-and-paricalcitol-treated groups. The effects of mono and combined therapy with paricalcitol and enalapril on testicular functions, sperm activity, glycemic state oxidative stress, and inflammatory parameters, as well as histopathological examinations, were assessed in comparison with the normal and diabetic control rats.

RESULTS

As a result of diabetes induction, epididymal sperm count, sperm motility, serum levels of testosterone, follicle-stimulating hormone (FSH) as well as luteinizing hormone (LH), and the antioxidant enzyme activities, were significantly decreased, while abnormal sperm (%), insulin resistance, nitric oxide (NO), malondialdehyde (MDA), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were significantly increased, along with severe distortion of the testicular structure. Interestingly, treatment with paricalcitol and enalapril, either alone or in combination, significantly improved the sperm parameters, increased antioxidant enzyme activities in addition to serum levels of testosterone, FSH, and LH, reduced insulin resistance, IL-6, and TNF-α levels, and finally ameliorated the diabetes-induced testicular oxidative stress and histopathological damage, with somewhat superior effect for paricalcitol monotherapy and combined therapy with both drugs compared to monotherapy with enalapril alone.

CONCLUSIONS

Monotherapy with paricalcitol and its combination therapy with enalapril has a somewhat superior effect in improving diabetes-induced testicular dysfunction (most probably as a result of their hypoglycemic, antioxidant, anti-inflammatory, and anti-apoptotic properties) compared with monotherapy with enalapril alone in male rats, recommending a synergistic impact of both drugs.

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.

Losartan ameliorates ovarian ischaemia/reperfusion injury in rats: an experimental study

This study aimed to investigate the protective and antioxidant role of losartan in ovarian ischaemia and ischaemia/reperfusion injury in an experimental ovarian torsion model. Thirty adult female rats were used. Rats were separated randomly into five groups; Group 1: sham group (abdominal wall was only opened and closed), Group 2: torsion group with 3-hour ischaemia using atraumatic vascular clips. Group 3: torsion + losartan group with 3-hour ischaemia 30 minutes after the administration of 40 mg/kg of losartan via oral gavage. Group 4: torsion-detorsion group with 3-hour ischaemia and 3-hour reperfusion (vascular clips were removed). Group 5: torsion-detorsion + losartan group with 3-hour ischaemia followed by administration of 40 mg/kg of losartan 30 minutes prior to a 3-hour detorsion/reperfusion. Ovarian tissue damage was scored by histopathological analysis. Ovarian tissue malondialdehyde (MDA) and plasma pentraxin 3 (PTX 3) levels were measured biochemically. In comparison with the sham group, both the torsion and torsion-detorsion groups had significantly higher scores for follicular degeneration, vascular congestion, oedema, haemorrhage, and leukocyte infiltration (p < .05). The aforementioned parameters significantly decreased in the torsion-detorsion + losartan group (p < .01) compared to those in the torsion-detorsion group. MDA and plasma PTX 3 levels were notably higher both in the torsion and torsion-detorsion groups compared with those in the sham group (p < .01). The current experimental ovarian torsion study suggests a protective role for losartan upon ischaemia and ischaemia/reperfusion injury in rat ovaries. Losartan may be a novel agent for decreasing ovarian ischaemia/reperfusion injury in ovaries.Impact statementWhat is already known on this subject? Among gynaecological emergencies, the diagnosis of ovarian torsion is highly difficult. A delayed diagnosis may lead to ovarian necrosis and subsequent loss of ovaries if timely surgical intervention is not performed, which is essential for the fertility and protection of ovarian functions in young patients. However, reperfusion of the ischaemic tissue might leads to more serious damage to the tissue than the damage caused by ischaemia.What the results of this study add? This study found that losartan, an Ang II type 1 receptor blocker which has been currently used for regulation of blood pressure, could be used experimentally to alleviate I/R injury in ovary through improving histological parameters, reducing tissue MDA and plasma PTX3 levels. To date, there is no study regarding the usage of losartan for alleviating I/R on ovary due to torsion.What the implications are of these findings for clinical practice and/or further research? Losartan may be suggested to have therapeutic value in patients with ovarian torsion. Further large clinical studies are necessary to prove the beneficial effect of losartan to prevent I/R injury on human ovaries.

New highlights on the health-improving effects of sulforaphane

In this paper, we review recent evidence about the beneficial effects of sulforaphane (SFN), which is the most studied member of isothiocyanates, on both in vivo and in vitro models of different diseases, mainly diabetes and cancer. The role of SFN on oxidative stress, inflammation, and metabolism is discussed, with emphasis on those nuclear factor E2-related factor 2 (Nrf2) pathway-mediated mechanisms. In the case of the anti-inflammatory effects of SFN, the point of convergence seems to be the downregulation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), with the consequent amelioration of other pathogenic processes such as hypertrophy and fibrosis. We emphasized that SFN shows opposite effects in normal and cancer cells at many levels; for instance, while in normal cells it has protective actions, in cancer cells it blocks the induction of factors related to the malignity of tumors, diminishes their development, and induces cell death. SFN is able to promote apoptosis in cancer cells by many mechanisms, the production of reactive oxygen species being one of the most relevant ones. Given its properties, SFN could be considered as a phytochemical at the forefront of natural medicine.

Testosterone induces apoptosis in cardiomyocytes by increasing proapoptotic signaling involving tumor necrosis factor-α and renin angiotensin system

Anabolic androgenic steroids lead to cardiac complications and have been shown to exhibit proapoptotic effects in cardiac cells; however, the mechanism involved in those effects is unclear. The aim of this study was to assess whether apoptosis and the activation of caspase-3 (Casp-3) induced by testosterone in high concentrations involves increments in tumor necrosis factor-α (TNF-α) concentrations and angiotensin-converting enzyme (ACE) activity in cardiomyocytes (H9c2) cell cultures. Cardiomyocytes were treated with testosterone (5 × 10−6 mol/L), doxorubicin (9.2 × 10−6 mol/L), testosterone + etanercept (Eta; 6.67 × 10−5 mol/L), testosterone + losartan (Los; 10−7 mol/L), and testosterone + AC-DEVD-CHO (10−5 mol/L; Casp-3 inhibitor). Apoptosis was determined by flow cytometry and by the proteolytic activity of Casp-3. We demonstrated that incubation of H9c2 cells for 48 h with testosterone causes the apoptotic death of 60–70% of the cells and co-treatments with Eta, Los, or AC-DEVD-CHO reduced this effect. Testosterone also induces apoptosis (concentration dependent) and increases the proteolytic activity of Casp-3, which were reduced by co-treatments. TNF-α and ACE activities were elevated by testosterone treatment, while co-treatment with Los and Eta reduced these effects. We concluded that an interaction between testosterone, angiotensin II, and TNF-α induced apoptosis and Casp-3 activity in cultured cardiomyocytes, which contributed to the reduced viability of these cells induced by testosterone in toxic concentrations.

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.

The hypoxic testicle: physiology and pathophysiology

Mammalian spermatogenesis is a complex biological process occurring in the seminiferous tubules in the testis. This process represents a delicate balance between cell proliferation, differentiation, and apoptosis. In most mammals, the testicles are kept in the scrotum 2 to 7°C below body core temperature, and the spermatogenic process proceeds with a blood and oxygen supply that is fairly independent of changes in other vascular beds in the body. Despite this apparently well-controlled local environment, pathologies such as varicocele or testicular torsion and environmental exposure to low oxygen (hypoxia) can result in changes in blood flow, nutrients, and oxygen supply along with an increased local temperature that may induce adverse effects on Leydig cell function and spermatogenesis. These conditions may lead to male subfertility or infertility. Our literature analyses and our own results suggest that conditions such as germ cell apoptosis and DNA damage are common features in hypoxia and varicocele and testicular torsion. Furthermore, oxidative damage seems to be present in these conditions during the initiation stages of germ cell damage and apoptosis. Other mechanisms like membrane-bound metalloproteinases and phospholipase A2 activation could also be part of the pathophysiological consequences of testicular hypoxia.

Role of angiotensin and endothelin in testicular ischemia reperfusion injury

OBJECTIVES

To determine whether angiotensin and endothelin have any role in testicular ischemia reperfusion injury by investigating the effects of the angiotensin converting enzyme inhibitor enalapril, selective non-peptide angiotensin-II type I blocker losartan and dual endothelin receptor blocker bosentan.

METHODS

Rats were anesthetized with thiopental sodium (50 mg/kg i.p.) before the operation. The left testicular artery and vein of rats were occluded for 1 h; before the bilateral orchiectomy, the organ was allowed to reperfuse for 3 h or 24 h. Enalapril (20 mg/kg i.p.), losartan (30 mg/kg i.p.), bosentan (10 mg/kg i.p.) or vehicle (saline) were given 30 min before reperfusion. Malondialdehyde level was measured in testicular tissue after 3 h of reperfusion. Histological examination was carried out after 24 h of reperfusion.

RESULTS

Ischemia reperfusion caused a significant increase in malondialdehyde level of ipsilateral testis, and histopathological injury in both ipsilateral and contralateral testes. Enalapril, losartan and bosentan treatments prevented the ischemia reperfusion-induced augmentation in malondialdehyde levels. Only bosentan treatment ameloriated ischemia reperfusion-induced histopathological alterations.

CONCLUSIONS

Endothelin might play a more important role in pathogenesis of testicular ischemia reperfusion injury when compared with angiotensin.

Comparison of the protective effects of papaverine, lidocaine and verapamil on the sperm quality of the testis after induced torsion-detorsion in rats

OBJECTIVE

Spermatic cord torsion is a true urological emergency. Significant subfertility exists in patients following unilateral testicular torsion. Several studies have tested several agents such as vasodilators and antioxidants to inhibit or temper testicular damage.

MATERIAL AND METHODS

Sprague-Dawley rats were divided into five groups; in group 1 (control) no operation or drug injection was done. In groups 2-5 the left testis was subjected to 270 torsions. Two hours after induced torsion, drugs were injected intraperitoneally. Rats in group 2 received no drug, whereas those in groups 3, 4 and 5 were administered a single dose of papaverine (35 mg/kg), lidocaine (4 mg/kg) and verapamil (0.1 mg/kg), respectively. Thirty minutes after drug injection (2.5 h after torsion), testis detorsion was performed in all groups. The drug injections continued for 1 week. After 20 days, bilateral orchiectomy was carried out and semen from both testes was evaluated.

RESULTS

In animals treated with verapamil, left testis sperm count and the percentage of motile sperm were increased significantly in comparison with the sham-operated animals. Sperm morphology in all groups was in the normal range. Mean sperm count and motility in the right testes were not significantly different in different groups.

CONCLUSIONS

Verapamil can induce beneficial effects on semen analysis parameters after testicular torsion in rats.