Ameliorative effect of vitamin E on aflatoxin-induced lipid peroxidation in the testis of mice

Aim: To evaluate the ameliorative effect of vitamin E on aflatoxin-induced lipid peroxidation in the testis. Methods: Adult male albino mice were orally administered 25 or 50 μg of aflatoxin in 0.2 mL olive oil per d for 45 d. The testis was isolated, blotted free of blood and processed for biochemical analysis. Results: There was a dose-dependent significantly higher lipid peroxidation in the testis of aflatoxin treated mice than in the controls. The levels of non-enzymatic antioxidants such as glutathione, total and reduced ascorbic acid, as well as the activities of enzymatic antioxidants, such as superoxide dismutase, glutathione peroxidase and catalase were significantly lower in the testis of aflatoxin treated mice. Vitamin E (2 mg/d per animal; orally) pretreatment significantly ameliorates the aflatoxin-induced lipid peroxidation which could be due to higher enzymatic and non-enzymatic antioxidants in the testis of mice as compared with those given aflatoxin alone. Conclusion: Vitamin E pretreatment significantly ameliorates aflatoxininduced lipid pemxidation in the testis of mice.     

Effects of melatonin on lipid peroxidation and antioxidant enzymes in streptozotocin-induced diabetic rat testis

Aim:To examine the effects of melatonin treatment on lipid peroxidation(LPO)and the activities of antioxidantenzymes in the testicular tissue of streptozotocin(STZ)-induced diabetic rats.Methods:Twenty-six male rats wererandomly divided into three groups as follows:group Ⅰ,control,non-diabetic rats(n=9);group Ⅱ,STZ-induced,untreated diabetic rats(n = 8);group Ⅲ,STZ-induced,melatonin-treated(dose of 10 mg/kg-day)diabetic rats(n=9).Following 8-week melatonin treatment,all rats were anaesthetized and then were killed to remove testes from thescrotum.Results:As compared to group Ⅰ,in rat testicular tissues of group Ⅱ,increased levels of malondialdehyde(MDA)(P<0.01)and superoxide dismutase(SOD)(P<0.01)as well as decreased levels of catalase(CAT)(P<0.01)and glutathione peroxidase(GSH-Px)(P>0.05)were found.In centrast,as compared to group Ⅱ,in rat testiculartissues of group Ⅲ,levels of MDA decreased(but this decrease was not significant,P>0.05)and SOD(P<0.01)aswell as CAT(P<0.05)increased.GSH-Px was not influenced by any of the treatment.Melatonin did not signifi-cantly affect the elevated glucose concentration of diabetic group.At the end of the study,there was no significantdifference between the melatonin-treated group and the untreated group by means of body and testicular weight.Conclusion:Diabetes mellitus increases oxidative stress and melatonin inhibits lipid peroxidation and might regulatethe activities of antioxidant enzymes of diabetic rat testes.(Asian J Androl 2006 Sep;8:595-600)     

Antioxidant enzymes activity,lipid peroxidation,oxidative damage in the testis and epididymis,and steroidogenesis in rats after co‐exposure to atrazine and ethanol

Concomitant alcohol use and exposure to xenobiotics can adversely affect gonadal functions. This study investigated the oxidative status of the testis and epididymis and steroidogenesis of rats co‐exposed to ethanol (EtoH, 5 mg kg^?1 b.wt.) and atrazine (ATZ, 50, 100, 300 mg kg^?1 b.wt.) for 3 weeks. The activities of catalase, superoxide dismutase, glutathione peroxidase, as well as the concentrations of glutathione and malondialdehyde, as indicators of oxidative stress were measured in the homogenates of the testis and epididymis. Testosterone and cholesterol concentrations as well as 17β‐hydroxysteroid dehydrogenase (17β‐HSD) activity were assayed in the plasma and testis respectively. After the administration of EtoH alone, or in combination with different doses of ATZ, oxidative damage as evident by malondialdehyde level was not observed in both the testis and epididymis. The combine exposure group showed dose‐dependent decrease in plasma testosterone and testis cholesterol level and increase in testis 17β‐HSD activity compared to the EtoH group. Furthermore, the testes and epididymis of the EtoH‐exposed rats treated with high dose of ATZ had severe histopathological damage. Therefore, ATZ‐exposed alcohol‐treated rats have histological damage of the testis and epididymis and lower testosterone level than EtoH‐treated rats.     

Testosterone-induced changes in testicular antioxidant system

Summary. In order to investigate the role of testosterone propionate (TP) on the antioxidant system of the rat testis, lipid peroxidation (LPX) and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) of the testis of testosterone-treated and control rats were compared. The results indicate that TP administration to intact adult rats resulted in a significant decline in protein content of various subcellular fractions. This is accompanied with significant elevation in LPX levels of various sub-cellular fractions suggesting induction of oxidative stress. Activities of three enzymes related to the metabolism of superoxide radical (SOD) and hydrogen peroxide (CAT and GPx) of testis, were found to be significantly decreased in response to TP treatment. The role of testosterone in regulating testicular spermatogenesis through oxidative stress is discussed.     

Administration of noradrenaline in the autonomic ganglia modifies the testosterone release from the testis using an ex vivo system

The male gonad receives nerve fibres from the autonomic ganglionic system. These fibres converge on the testis along two pathways, the superior and the inferior spermatic nerves. The superior spermatic nerve runs from the superior mesenteric ganglion alongside the testicular artery, whereas the inferior spermatic nerve originates in inferior mesenteric ganglion, accompanies the vas deferens and penetrates the inferior pole of the testis. The aim of this work was to evaluate androgen release after the addition of noradrenaline or adrenoreceptor antagonists (propranolol or phentolamine) to the ganglionic compartment. An ex vivo system used in a previous work was incubated in two separate containers, one for the testis and the other for the ganglion. Both organs remain interconnected (as in vivo) by the respective spermatic nerve. When noradrenaline was added to the inferior mesenteric ganglion, testosterone release in the gonad container underwent a progressive and significant increment. Propranolol diminishes and phentolamine increases the androgen release. When using the superior mesenteric ganglion, no changes were observed. These results indicate that the ganglionic stimulation of the autonomic system clearly participates in testosterone release from the testis. This effect depends on the ganglion involved. These results make it evident that not only the classical and well-known hypothalamus–hypophysial axis, but also the peripheral nervous system, via the autonomic ganglia, are directly involved in the endocrine control of the testis.     

Protective effects of silymarin on testis histopathology,oxidative stress indicators,antioxidant defence enzymes and serum testosterone in cadmium‐treated mice

Cadmium is known as an oxidative stress‐inducing factor. Silymarin extracted from Silybum marianum is regarded as a potent antioxidant. The present study investigated the preventing effects of silymarin on cadmium chloride‐induced toxicity in terms of testis histopathology and serum testosterone level as well as oxidative stress indicators in mice. In addition, the activities of antioxidant defence enzymes was evaluated. Adult male mice were divided into four groups (n = 6 in each group): (a) control; (b) cadmium chloride; (c) silymarin + cadmium chloride and (d) Silymarin. In this study, cadmium chloride significantly decreased the diameter and wall thickness of the seminiferous tubule, diameter of the spermatogonia nucleus and serum testosterone levels compared to the control group. Furthermore, in mice treated with this pollutant, a significant increase in malondialdehyde was observed while ferric reducing antioxidant power level, and the activity of catalase, superoxide dismutase and glutathione peroxidase were significantly reduced in the testis. In the silymarin + cadmium chloride group, silymarin could significantly reverse the toxic effects of cadmium chloride. The findings of this study showed that silymarin, as a potent antioxidant, can compensate the adverse effects of cadmium chloride on testis histopathology, testosterone level, oxidative stress indicators and antioxidant defence enzymes in mice.     

Effects of local heating of the testes on the concentration of testosterone in jugular and testicular venous blood of rats and on testosterone production in vitro

Heating both testes of rats to between 39 degrees C and 41 degrees C for 30 min was apparently without effect 21 days later, but heating to between 41.5 degrees C and 43 degrees C for 30 min resulted in a significant drop in testis weight accompanied by significant rises in the serum levels of LH and FSH. There were no changes in serum testosterone concentration in the peripheral circulation although there were increases in the concentration in testicular venous blood. The ability of the heated testis to secrete testosterone in vivo in response to maximal stimulation by hCG was reduced, as judged by testosterone levels in peripheral blood, while there was a supranormal increase in testosterone levels in testicular venous blood. Maximally stimulated testosterone production in vitro by the heated testis was supranormal whereas the basal production of testosterone per testis was not different from control values. Therefore, it appears that the testosterone produced by Leydig cells from heated testes may not be secreted as effectively as in normal testes.     

维生素E拮抗铬致大鼠睾丸毒性作用的实验研究

为研究维生素Ｅ对铬酸钾（Ｋ２ＣｒＯ４）所致大鼠睾丸毒性的影响，将大鼠分为４组，其中３组口服Ｋ２ＣｒＯ４（１０ｍｇ／ｋｇ体重），第二组加服维生素Ｅ（５ｍｇ／ｋｇ），第三组按２０ｍｇ／ｋｇ体重加服维生素Ｅ，连续服药３０天后，通过光镜检查，结果发现：单纯服用Ｋ２ＣｒＯ４１０ｍｇ／ｋｇ组的大鼠睾丸曲精管不同程度变性，管内生精细胞数目减少、缺如，精子形成少或者无。而用Ｋ２ＣｒＯ４（１０ｍｇ／ｋｇ）染毒同时加     

Annexin5对雄性SD大鼠生殖相关指标和睾酮分泌的影响

目的 探讨膜联蚩白5(annexin5)对雄性SD大鼠体重、睾丸系数、附睾系数、精子相对计数和睾酮水平的影响.方法 给雄性SD大鼠腹腔注射3个不同剂量(7.5μg/kg、15μg/kg、30μg/kg)的annexin5,对照组腹腔汴射等晕的pH 8.0 Tris-HCI,1次/d,连续20d.分别称重对照组和实验组SD大鼠体重、睾丸、附睾,并对附睾尾进行精子计数.HE染色观察睾丸组织结构.运用化学发光法检测对照组和各实验组SD大鼠血清中睾酮浓度.结果 与对照组相比,15 μg/kg实验组大鼠附睾系数与精子相对计数均显著提高,分别提高了12.5%(131.8±9.6vs 117.2±5.9)(P<0.01)和31.4%(36.8±5.6vs 31.7±5.3)(P<0.05);其它剂量组与对照纰相比差异均无统计学意义(P>0.05).HE染色显示各剂量实验组与对照组相比,睾丸的形态结构没有发牛明显改变.7.5 μg/kg组和15 μg/kg组大鼠血清睾酮含量显著高十对照组,分别提高了35.5%(36.33±3.89vs26.82±3.75)(P<0.01)和82.8%(49.04±5.17vs26.82±3.75)(P<0.01),30 μg/kg组大鼠睾酮含量虽也有升高,但与对照组比较,结果无统计学意义(P>0.05).结论 腹腔注射annexin5能影响大鼠睾丸生精、附睾功能及睾酮水平,并与剂量有关.     

Changes in intratesticular testosterone, cytoplasmic androgen receptors and ABP content of the ram testis after a single endogenous pulse of LH

The effects of an endogenous LH pulse on the testicular concentration of testosterone, cytoplasmic androgen receptor content and androgen binding protein (ABP) content was studied in rams. Blood was collected from 36 rams for at least 14 h and their testes then removed. Animals were then grouped according to the interval from their last LH pulse and the time of slaughter. The concentration of testosterone in the testis was highest during the first h following the LH pulse and returned to its baseline within 5 h. There was a 60% reduction in the testicular content of cytoplasmic androgen receptors at 3 h after the LH pulse, followed by slow replenishment. The testicular content of ABP was highest at 4 h after the LH pulse. It is in the testis concluded that the pulsatility of LH and testosterone induces a pulsatile translocation of cytoplasmic androgen receptors.     

Stereological study of the effects of vitamin E on testis structure in rats treated with para-nonylphenol

This study was organized to see whether vitamin E, as a strong antioxidant, could affect the abnormalities of testis structure caused by para-nonylphenol （p-NP） during its development. A total of 32 female Wistar rats after mating were divided into four groups （n = 8）： control, vitamin E （100 mg kg^-1 per day）, p-NP （250 mg kg^-1 per day） and p-NP ＋ vitamin E. The rats were treated from the seventh day of pregnancy till the twenty-first day. After weaning, the male pups were divided into the same groups and were treated orally for 90 days. Finally, the right testis was fixed, processed, stained and studied using stereological methods. The weight and volume of testis, volume of seminiferous tubules and its diameter, thickness of the basement membrane, height of the germinal epithelium, total number of types A and B spermatogonia, spermatocyte, spermatid and Sertoli cells were significantly reduced in p-NP group when compared with other groups. Co-administration of vitamin E and p-NP compensated for the adverse effects of p-NP on the above parameters. In addition, treatment with only vitamin E caused a significant increase in diameter, basement membrane thickness and height of germinal epithelium, number of spermatogonia and spermatocytes. Co-administration of vitamin E with p-NP could prevent the adverse effects ofp-NP on the testis structure during its development.     

Effects of levonorgestrel butanoate alone and in combination with testosterone buciclate on spermatogenesis in the bonnet monkey

The spermatogenic effects of levonorgestrel butanoate were studied in adult male bonnet monkeys when administered alone and in combination with testosterone buciclate. Levonorgestrel butanoate (0.25, 1.0 and 2.5 mg kg(-1)) given as two injections on days 0 and 60 (groups II, III, IV) resulted in thickening and folding of the basement membrane and disruption of cell associations in groups III and IV (on day 120). In group II, no apparent changes in testicular histology were observed. When these doses of levonorgestrel butanoate were combined with 40 mg of testosterone buciclate (groups V, VI, VII), maximum changes were seen in group VI in which all stages of spermatogenesis were absent on day 120 except for a small number of spermatogonia. The changes caused by lower dose (group V) and higher dose (group VII) of levonorgestrel butanoate were less prominent than in group VI. A significant decrease in the number of dark A (Ad) and B spermatogonia was observed in all groups except for Ad spermatogonia on day 120 in group V, B spermatogonia on day 60 in group IV and B spermatogonia on day 120 in group III. A significant decrease in pachytene spermatocytes was seen on day 120 in groups V only. Early spermatids showed a significant decrease only in groups V and VII on day 120 of treatment. Advanced spermatids were suppressed significantly in group IV on day 60 and in groups IV and V on day 120. These data indicate that levonorgestrel butanoate (1.0 mg kg(-1)) in combination with 40 mg of testosterone buciclate was the most effective treatment in suppressing spermatogenesis. The site of action of this combination regimen is at the level of renewing Ad spermatogonia.     

Reversible effect of testosterone undecanoate injection on spermatogenesis in rats

Aim: To study the effect of testosterone undecanoate (TU) injection on spermatogenesis in rats. Methods: Twenty adult SD rats received vehicle or TU (8 mg/kg, 19 mg/kg or 025 mg/kg) injection, im, every 15 days for days, and another 38 animals received similar treatments for 130 days with half of them undergoing a recovery phase of 120 days (5 rats for each treatment). At the end of the treatment, testes were removed and the diameter of the seminiferous tubules and the number of late elongated spermatids ( steps 15 - 19 ) per testis were estimated with stereological methods as a measure of the spermatogenic efficiency. Results: Low dose (8 mg/kg) TU treatment virtually had no effect on spermatogenesis. A dose of 19 mg/kg slightly suppressed spermatogenesis 60 days after treatment, and severe suppression occurred after another 70 days of dosing. Spermatogenesis was completely recovered at the end of the recovery phase. Large dose (625 mg/kg) TU treatment did not significantly affect spermatogenesis and was well tolerated by animals. Conclusion: TU injection reversibly suppresses spermatogenesis in rats.     

Experimentally induced hypo- and hyper-thyroidism influence on the antioxidant defence system in adult rat testis

The objective of the present experiment was to study the effect of thyroid hormone on the antioxidant defence system of rat testis. Hypothyroidism induced in rats by 6-n propyl 2-thiouracil (PTU) treatment resulted in a reduction in body weight, seminal vesicle and ventral prostate gland. A further decrease in the weight of seminal vesicle was recorded following administration of T3 to hypothyroid rats. The oxidative stress parameters such as hydrogen peroxide and protein carbonyl content increased in the crude homogenate of testis of hypothyroid rats. T3 administration to hypothyroid rats resulted in no further change in the hydrogen peroxide level but the protein carbonyl content further elevated in the crude homogenate of testis. No significant change was observed in the endogenous lipid peroxidation level of the crude homogenate of testis whereas the FeSO4/ascorbic acid induced lipid peroxidation level decreased in hypothyroid rats and did not change further by T3 administration. Although the reduced glutathione level in the crude homogenate of testis did not change following hypothyroidism, oxidized glutathione level increased. The reduced and oxidized glutathione level decreased and increased, respectively following T3 administration to hypothyroid rats in comparison with PTU-treated rats. Activities of superoxide dismutase and catalase decreased in the post-mitochondrial fraction (PMF) of testis of hypothyroid rats. T3 injection to PTU-treated rats resulted in an elevation in the level of catalase activity only. The activity of glutathione peroxidase in the PMF of testis elevated in the hypothyroid rats and reduced following T3 treatment to hypothyroid rats. The results of the present study suggest that any alteration in the thyroid hormone level in the body affects the antioxidant defence system of testis of adult rats and, thereby, may affect the physiology of testis through oxidative stress.     

Administration of acetylcholine to the spermatic nerve plexus inhibits testosterone secretion in an in vitro isolated rat testis-nerve plexus system

Strong evidence indicated that spermatic nerves are involved in the regulation of testosterone secretion. Our previous work showed that the inferior spermatic nerves play a more significant role than the superior ones in the regulation of testosterone secretion. However, it is unknown whether traditional neurotransmitters are involved in this regulation. In order to evaluate this point, the present experiments were carried out in an in vitro system where an isolated testis-spermatic nerve plexus preparation was incubated in two separate containers, one for the testis and the other for the nerve plexus and both interconnected by the inferior spermatic nerves. Both tissues were maintained in the same environmental conditions except for the neurotransmitter treatment, applied only to the nerve plexus. Acetylcholine can significantly inhibit the secretion of testosterone until the end of incubation. The present experiments suggest that the secretion of testosterone could be regulated, at least in part, by acetylcholine through the inferior spermatic nerves.     

Effects of local heating of the testis on testicular blood flow and testosterone secretion in the rat

Exposure of one or both testes of rats to heating at 43 degrees C for 30 min resulted in a significant reduction in blood flow per testis, as measured using microspheres. The effects on the testes of unilateral and bilateral heating were similar, although the changes in FSH levels in peripheral blood were in general less marked after unilateral heating. Testicular blood flow fell, along with testicular weight, beginning at 2-4 days and reaching minimum values 14-21 days after heating. Both blood flow per testis and testicular weight were beginning to recover 35 days post-heating and blood flow per testis was normal by 56 days following heat treatment, although testicular weight was still slightly reduced at that time. Heating one or both testes to 42 degrees C produced similar but smaller responses 21 days later, whereas temperatures of 41 degrees C or lower were without effect on the parameters measured, except for some rises in serum LH and FSH. With slight reductions in blood flow, there were corresponding increases in testicular venous testosterone concentration so that testosterone secretion was unaffected. Further reductions in blood flow at 14 and 21 days after heating to 43 degrees C were not fully compensated by an increase in the concentration of testosterone in testicular venous blood, with the result that testosterone secretion fell.     

Effect of vitamin E on human sperm motility and lipid peroxidation in vitro

Aim: To assess the protective efficacy of vitamin E to counteract the reactive oxygen species (ROS) mediated damage onsperm motility, viability and lipid peroxidation. Melhods: Human semen samplns were obtained from the local hospi-tal. The split seminal fractions freed of seminal plasma v, ere reeonstimted in Ringer-Tymde and subjected to varied vita-min E concentrations (0.1-2 mmol/L), Results: Dose-dependent improvement in both motility and viability accom-panied by concomitant decrease in malondialdehyde (MDA an end product of lipid peroxidation) following vitamin Esuppllementation was noticed. Conclusion: Vitamin E protects against the ROS mediated damage on spermatozoa.Vimmth E supplementation could be of clinical importance for prolonged spermatozoal storage whenever needed.     

Effect of sodium arsenite on spermatogenesis,plasma gonadotrophins and testosterone in rats

To investigate the effect of arsenic on spermatogenesis. Methods: Mature (4 months old) Wistar rats were intraperitoneally administered sodium arsenite at doses of 4, 5 or 6 mg-kg^-day1 for 26 days. Different varieties of germ cells at stage VII seminiferous epithelium cycle, namely, type A spermatogonia (ASg), preleptotene spermatocytes (pLSc), midpachytene spermatocytes (mPSc) and step 7 spermatids (7Sd) were quantitatively evaluated, along with radioimmunoassay of plasma follicle-stimulating hormone (FSH), lutuneizing hormone (LH), testosterone and assessment of the epididymal sperm count. Results: In the 5 and 6 mg/kg groups, there were significant dose-dependent decreases in the accessory sex organ weights, epididymal sperm count and plasma concentrations of LH, FSH and testosterone with massive degeneration of all the germ cells at stage VII. The changes were insignificant in the 4 mg/kg group. Conclusion: Arsenite has a suppressive influence on spermatogenesis and gonadotrophin and testosterone r     

Effect of testicular capsulotomy on secretion of testosterone and gonadotrophins in rats

Aim: In order to clarify further the mechanisms underlying the effect of capsulotomy on testicular function, the levels of testosterone, LH and FSH were observed. Methods: Intratesticular testosterone levels and LH, FSH levels in the peripheral blood of normal, sham-operated and capsulotomized rats were detected by RIA. Results: After testicular capsulotomy, there was a progressive reduction in the testosterone level in the testicular venous blood together with a progressive increase in the LH and FSH levels in the peripheral blood from approximately 30 days post-capsulotomy. Morphological changes were observed at 5-10 days after capsulotomy, i.e., far ahead of the hormonal changes.Conclusion: The seminiferous tubular damage after testicular capsulotomy was not caused by the reduction in testosterone, and on the contrary, the hormonal change might be secondary to the morphological alterations. The increase in LH level most likely resulted from a negative feedback influence from the lowered testosterone level, while the increase in FSH secretion may be a feedback signal of the damaged seminiferous tubules. (Asian J Androl 2000 Dec;2:257-261)     

Effects of exposure to a mobile phone on testicular function and structure in adult rabbit

The accumulating effects of exposure to electromagnetic radiation emitted by a conventional mobile phone (standby position) on the testicular function and structure are not yet fully investigated. To study these effects longitudinally, a total of 24 adult male rabbits were randomly and equally divided into three groups. Rabbits in the first (phone) group were exposed, in specially designed cages, to radio frequency emitted from the mobile phone (800 MHz) in a standby position opposite to that of testes for 8 h daily for 12 weeks. The second group consisted of the stress controls which were kept in the same kind of cages to appreciate any cage-induced anxiety. The third group included the ordinary controls which were kept in the conventional roomy cages. Semen analysis and sperm function tests (viability, hypo-osmotic swelling and acridine orange) were conducted weekly. Histological testicular sections and serum total testosterone were also evaluated. A drop in the sperm concentration appeared in the phone group at week 6. This became statistically significant at week 8, compared with the two control (stress and ordinary) groups (133, 339 and 356 × 106/mL, respectively) and to the initial sperm count (341 × 106/mL) of this group. Motile sperm population showed similarity amongst the three study groups until week 10 when it declined significantly, and thereafter in the phone and stress control groups, with more significant decline in the phone animals (50, 61 and 72.4%, respectively). Histological examination showed also a significant decrease in the diameter of seminiferous tubules in the phone group vs. the stress and ordinary controls (191 μm vs. 206 and 226 μm, respectively). The other study points did not show any difference. In conclusion, low intensity pulsed radio frequency emitted by a conventional mobile phone kept in the standby position could affect the testicular function and structure in the adult rabbit.