Beneficial Effects of Renin-Angiotensin System Blockers on Testicular Steroidogenesis

Oat Beta-Glucan Dietary Intervention on Antioxidant Defense Parameters, Inflammatory Response and Angiotensin Signaling in the Testes of Rats with TNBS-Induced Colitis

Male infertility represents a significant public health concern. There is a negative impact of inflammatory bowel diseases (IBDs) on the male reproductive system. The aim of this study was to investigate whether oat beta-glucan (OBG) with different molar mass can modulate parameters of antioxidant defense and inflammatory response in the testes of adult Sprague-Dawley rats with TNBS-induced colitis and whether the OBG intervention can modulate the inflammatory response in association with the RAS system. Results: higher testicular superoxide dismutase (SOD), glutathione reductase (GR) activities and glutathione (GSH) concentration, and lower testosterone (T) level and glutathione peroxidase (GPx) activity, were observed in rats with colitis than in healthy control ones. TNBS-induced colitis resulted in decreased the angiotensin 1-7 (ANG 1-7) level in the testes of rats fed with low-molar mass OBG compared to control animals. Conclusions: although colitis induced moderate pro-oxidant changes in the gonads, it seems plausible that dietary intervention with different fractions of oat beta-glucans mass may support the maintenance of reproductive homeostasis via the stimulation of the local antioxidant defense system.

Cratoxylum formosum dyer extract alleviates testicular damage in hypertensive rats

The effects of a Cratoxylum formosum (Jack) Dyer ssp. (CF) extract on testicular damage were assessed in hypertensive rats. N^ω -nitro-L-arginine methyl ester hydrochloride (L-NAME; 40 mg kg^-1  day^-1 ) was administered for 5 weeks to induce hypertension in male Sprague-Dawley rats, and treated with CF extract (100, 300 or 500 mg kg^-1  day^-1 ) or sildenafil (5 mg kg^-1  day^-1 ) during the final 2 weeks (n = 8/group). Biochemical components of the CF extract were identified and mainly contained phenolic compounds. The CF extract significantly reduced systolic blood pressure and alleviated impaired sperm quality and seminiferous tubular morphology in hypertensive rats. CF extract restored reduced serum testosterone and protein expression of steroidogenic acute regulatory protein (StAR), nuclear factor erythroid-related factor 2 (Nrf2), and haem oxygenase 1 (HO-1) in L-NAME rats. Hypertensive rats presented decreased antioxidant enzyme activities, and increased testicular and plasma malondialdehyde (MDA) levels and superoxide production, all of which were normalised by CF extract. Furthermore, endothelial nitric oxide synthase (eNOS) expression in testicular tissue and plasma nitrate/nitrite levels were restored in hypertensive rats administered CF extract. Conclusion: CF extract alleviated testicular damage in hypertensive rats. Potential molecular mechanisms may involve suppression of oxidative stress and restoration of StAR, Nrf2, HO-1 and eNOS expression in hypertensive rats.

Vitellogenins and choriogenins are biomarkers for monitoring Oryzias curvinotus juveniles exposed to 17 β - estradiol

The effect of estrogens on Oryzias curvinotus juveniles were investigated by sequencing the transcriptome of O. curvinotus juveniles exposed to 17 β - estradiol for 24 h. A total of 69,071,524 and 71,210,528 raw reads were obtained for the control group (NC) and 17 β - estradiol exposure group (E2), respectively. After de novo assembly, total 133,210 unigenes were identified, and 85,837 unigenes (64.44% of 133,210) were annotated. Analysis of the transcriptome showed that exposure to 2 μg/L 17 β - estradiol led to the up-regulation of 19 genes and down-regulation of 18 genes. The eef1b and rps4x was most suitable as controls for quantitative real-time PCR (qPCR) using Reffinder. Different expression genes enrichment analysis found that exposed to 2 μg/L 17 β - estradiol affected various physiological processes, including spliceosome, phototransduction, amino sugar and nuclear sugar metabolism, hypotaurine metabolism, and renin-angiotensin system, etc. Exposing O. curvinotus juveniles to increasing concentrations of 17 β - estradiol (2 ng/L, 20 ng/L, 200 ng/L and 2 μg/L) led to significant up-regulation of vitellogenins (vtgs) and choriogenins (chgs) mRNA expression. The present study is the first high-throughput transcriptome sequencing of O. curvinotus juveniles, which will be useful for future functional analysis of genes related to environmental estrogen exposed, and development of biomarkers.

Protective effects of tribulus terrestris extract and angiotensin blockers on testis steroidogenesis in copper overloaded rats

The rational of the current study was to assess whether Tribulus terrestris extract (TTE) could alleviate long-term copper (Cu) overload-induced testicular dysfunction compared to enalapril and losartan. Rats were administered either vehicle (control group, n = 10) or copper sulfate pentahydrate (CuSO₄·5H₂O, 200 mg/kg, p.o) for 90 days (n = 40). Cu-treated rats were randomized into four equal groups. One group was left untreated (Cu group) while the remaining three groups were daily co-treated with one of the following treatments along with CuSO4: TTE (10 mg/kg, p.o); enalapril (30 mg/kg, p.o); losartan (10 mg/kg, p.o). Excess Cu intake resulted in Cu overload coupled with a significant elevation in systolic blood pressure and serum angiotensin II levels along with a reduction in serum nitric oxide level. All concomitant treatments led to an alleviation of such deleterious effects. However, only losartan failed to ameliorate angiotensin II elevation. Additionally, all treatments protected the testes against Cu-overload-elicited zinc depletion and oxidative stress. Regarding reproductive function, the relative weights of testes, serum levels of testosterone and luteinizing hormone; the expression of steroidogenic genes; the protein levels of angiotensin II type 1 receptor and angiotensin converting enzyme 1, in addition to its activity, they were significantly reduced. Amongst all treatments, only TTE and E were able to revert these reproductive changes. In conclusion TTE and E were able to protect against Cu overload-induced impairment of testicular steroidogenesis. Thus, they might be considered as prophylactic drugs of choice against hypertension and testicular dysfunction to ameliorate Cu overload risk.

Influence of a Virgin Olive Oil versus Butter Plus Cholesterol-Enriched Diet on Testicular Enzymatic Activities in Adult Male Rats

The aim of the present work was to improve our knowledge on the mechanisms underlying the beneficial or deleterious effects on testicular function of the so-called Mediterranean and Western diet by analyzing glutamyl aminopeptidase (GluAP), gamma glutamyl transpeptidase (GGT) and dipeptidyl peptidase IV (DPP IV) activities in testis, as enzymes involved in testicular function. Male Wistar rats (6 months old) were fed for 24 weeks with three different diets: standard (S), an S diet supplemented with virgin-olive-oil (20%) (VOO), or a S diet enriched with butter (20%) plus cholesterol (0.1%) (Bch). At the end of the experimental period, plasma lipid profiled (total triglycerides, total cholesterol and cholesterol fractions (HDL, LDL and VDL)) were measured. Enzymatic activities were determined by fluorimetric methods in soluble (sol) and membrane-bound (mb) fractions of testicular tissue using arylamide derivatives as substrates. Results indicated an increase in plasmatic triglycerides, total cholesterol, LDL and VLDL in Bch. A significant increase of mb GluAP and GGT activities was also found in this diet in comparison with the other two diets. Furthermore, significant and positive correlations were established between these activities and plasma triglycerides and/or total cholesterol. These results support a role for testicular GluAP and GGT activities in the effects of saturated fat (Western diet) on testicular functions. In contrast, VOO increased sol DPP IV activity in comparison with the other two diets, which support a role for this activity in the effects of monounsaturated fat (Mediterranean diet) on testicular function. The present results strongly support the influence of fatty acids and cholesterol on testicular GluAP and GGT activities and also provide support that the reported beneficial influence of the Mediterranean diet in male fertility may be mediated in part by an increase of testicular sol DPP IV activity.

Beneficial Effects of Renin-Angiotensin System Blockers on Testicular Morphology

Background: The renin-angiotensin system (RAS) is a set of peptides, enzymes, and receptors specially involved in the control of extracellular fluid volume and blood pressure (BP); however, some of its components have already been identified in the testis, such as angiotensinogen, angiotensin converting enzyme, and renin. Objectives: The aim of this study was to evaluate whether renin-angiotensin system blockers have effects on the testicular morphology of animals fed a high energy density (HED) diet. Materials and Methods: Male C57BL/6 mice were fed initially a standard chow (SC) or a HED diet. After 8 weeks, HED animals were randomized into 4 groups, each group receiving one of the following treatments for the next 6 weeks: HED-A: aliskiren (50 mg/kg/d); HED-E: enalapril (30 mg/kg/d); HED-L: losartan (10 mg/kg/d); and untreated HED group. The BP was measured biweekly. At the end of treatment, all animals were killed and the testes were processed for morphometric and stereological parameters including density of seminiferous tubules per area, density of length and the total length of the seminiferous tubules, height of the epithelium, and diameter of the seminiferous tubules. Samples were tested for their homoscedasticity and the differences between the groups were tested by one-way analysis of variance (ANOVA), followed by the Holm-Sidak post-test. In all cases, the significance level adopted was P ≤ .05. Results: Compared to SC, HED groups presented an increase in BP, normalized by all RAS blockers. However, the HED diet caused testis alterations that were not affected by aliskiren or losartan. Only enalapril maleate was capable of reversing such alterations. Conclusions: Further studies are still needed to answer why only enalapril was able to reveal the morphological changes caused by the high energy diet; so enalapril could be suggested as the drug of choice for patients with previous reproductive dysfunction.

Cardiovascular/Pulmonary Medications and Male Reproduction

Cardiovascular and respiratory medications are used by men of reproductive age although use of the former is most prevalent in advanced age. Many of these drugs have been associated with sexual dysfunction, including erectile and ejaculatory dysfunction, but for most there is insufficient evidence to link their use with testicular dysfunction, reduced semen quality or infertility. Some exceptions are the irreversible α₁-adrenergic antagonist phenoxybenzamine, which carries a high risk of retrograde ejaculation; the specific α_1A-adrenergic antagonists silodosin and tamsulosin, used primarily to treat BPH/lower urinary tract symptoms, which can cause retrograde ejaculation; and the peripheral β₁-adrenergic antagonist atenolol, used to treat hypertension, which may decrease testosterone/free-testosterone levels. In this chapter, we review the evidence available regarding adverse reactions on male reproduction of adrenergic receptor agonists/antagonists, calcium channel blockers, angiotensin converting enzyme (ACE) inhibitors, diuretics, digoxin, and hydralazine. For some of these medications, there is some evidence for male reproductive effects, along with some solid work in experimental and companion animal species suggesting negative effects. In contrast, and of special note, are calcium channel blockers, which have long been included on lists of medications with the potential to cause male infertility. This turns out to be a good example of a substance with profound effects on sperm function in vitro, but with limited evidence for in vivo effects on semen quality or fertility, even in experimental species. We hope that the evidence provided in this chapter will stimulate additional studies for these important classes of medications.

Testicular transcript responses in rare minnow Gobiocypris rarus following different concentrations bisphenol A exposure

Bisphenol A (BPA) is widely spread in the environment. It can cause various reproductive disrupting effects on different organisms, including fish. To investigate the effect of BPA at different concentrations comprehensively, RNA-seq was performed on the testicular mRNA libraries of adult male rare minnow Gobiocypris rarus that exposed to 0, 1, 15 and 225 μg/L BPA for 7 days. Meanwhile, biological indicators and sex steroid hormone levels were investigated. Result showed that (1) BPA at all three concentrations affected the expression of genes related to testicular steroid hormone biosynthesis, blood-testis barrier, proteolysis, and lipid transport and metabolism. (2) BPA at 1 μg/L induced gene expression in renin-angiotensin system pathway and possibly initiate membrane form of estrogen receptor (mER); 1 and 15 μg/L BPA inhibited tRNA processing-related genes expression; 15 and 225 μg/L BPA decreased hemostasis and blood coagulation-related gene expression. The present study indicated that BPA did influence rare minnow testicular gene expressing, and the effect BPA effects varied with concentration.

Candesartan Mediated Amelioration of Cisplatin-Induced Testicular Damage Is Associated with Alterations in Expression Patterns of Nephrin and Podocin

Nephrin and podocin are known to be closely related to the pharmacological effects of angiotensin-II receptor blocker (ARB). The objectives of this study were to investigate the role of nephrin and podocin using cisplatin-induced testicular damage and to evaluate the effect of ARB. At first, we evaluated the effects of cisplatin either alone or in combination with ARB candesartan on changes in expression patterns of nephrin and podocin in the rat testes. We then conducted in vitro studies to investigate the effects of angiotensin using cultured Sertoli cells, line TM4. As a result, the expression of nephrin and podocin was shown to localize around the basal membrane of seminiferous tubules. Treatment with cisplatin resulted in a marked decrease in the expression of nephrin and podocin and induced a shift of both proteins from linear to granular expression patterns, accompanying the increased apoptotic index in the testes; these changes were partially restored by the additional administration of candesartan. In vitro studies with TM4 revealed the angiotensin-II mediated expression changes of nephrin and podocin. These findings suggest that candesartan can prevent cisplatin-induced testicular damage by regulating expression patterns of the nephrin-podocin complex in the testes.