Unraveling the impact of melatonin treatment: Oxidative stress, metabolic responses, and morphological changes in HuH7.5 hepatocellular carcinoma cells.

In addition to its highly aggressive nature and late diagnosis, hepatocellular carcinoma (HCC) does not respond effectively to available chemotherapeutic agents. The search is on for an ideal and effective compound with low cost and minimal side effects that can be used as an adjunct to chemotherapeutic regimens. One of the mechanisms involved in the pathology of HCC is the oxidative stress, which plays a critical role in tumor survival and dissemination. Our group has already demonstrated the antitumor potential of melatonin against HuH 7.5 cells. In the present study, we focused on the effects of melatonin on oxidative stress parameters and their consequences on cell metabolism. HuH 7.5 cells were treated with 2 and 4 mM of melatonin for 24 and 48 h. Oxidative stress biomarkers, antioxidant enzyme, mitochondrial membrane potential, formation of lipid bodies and autophagic vacuoles, cell cycle progression, cell death rate and ultrastructural cell alterations were evaluated. The treatment with melatonin increased oxidative stress biomarkers and reduced antioxidant enzyme activities of HuH 7.5 cells. Additionally, melatonin treatment damaged the mitochondrial membrane and increased lipid bodies and autophagic vacuole formation. Melatonin triggered cell cycle arrest and induced cell death by apoptosis. Our results indicate that the treatment of HuH 7.5 cells with melatonin impaired antioxidant defense systems, inhibited cell cycle progression, and caused metabolic stress, culminating in tumor cell death.

Exposure to aluminium chloride during the peripuberal period induces prostate damage in male rats.

Aluminium (Al) is an important metal, but it can be toxic including for prostate tissue. This study aimed to evaluate whether exposure to aluminium chloride (AlCl3) during the peripubertal period affects ventral prostate development in rats. Male Wistar rats (30 days old) were distributed into three experimental groups: control (sterile 0.9% saline solution), AL7 (7 mg AlCl3/kg) and AL34 (34 mg AlCl3/kg). Animals were treated intraperitoneally from postnatal day (PND) 36-66 (peripubertal period). At PND67, the animals were anaesthetized and euthanized. Blood was collected for testosterone levels. The ventral prostate (VP) was removed, weighed and processed for histochemistry and immunohistochemistry to detect androgen (AR) and Ki67. Stereological and histopathological analyses, mast cell counts, and determinations of myeloperoxidase (MPO) and N-acetyl glycosidase (NAG) activity and IL-6 levels were performed. The AL34 group presented a reduction in body weight and increase in MPO activity compared to the other groups. In both the AL7 and AL34 groups, there was reorganization of the prostatic tissue compartments. There was no significant difference in prostate weight, number of granulated or degranulated mast cells, or testosterone levels. In conclusion, the exposure to aluminium chloride during the peripubertal period impairs the prostatic development.

High-fructose diet during puberty alters the sperm parameters, testosterone concentration, and histopathology of testes and epididymis in adult Wistar rats.

The consumption of fructose has increased in children and adolescents and is partially responsible for the high incidence of metabolic diseases. The lifestyle during postnatal development can result in altered metabolic programming, thereby impairing the reproductive system and fertility during adulthood. Therefore, the aim of this study was to evaluate the effect of a high-fructose diet in the male reproductive system of pubertal and adult rats. Male Wistar rats (30 d old) were assigned to four different groups: Fr30, which received fructose (20%) in water for 30 d and were euthanized at postnatal day (PND) 60; Re-Fr30, which received fructose (20%) for 30 d and were euthanized at PND 120; and two control groups C30 and Re-C30, which received water ad libitum and were euthanized at PND 60 and 120, respectively. Fructose induced an increase in abnormal seminiferous tubules with epithelial vacuoles, degeneration, and immature cells in the lumen. Moreover, Fr30 rats showed altered spermatogenesis and daily sperm production (DSP), as well as increased serum testosterone concentrations. After discontinuing high-fructose consumption, DSP and sperm number decreased significantly. We observed tissue remodeling in the epididymis, with a reduction in stromal and epithelial compartments that might have influenced sperm motility. Therefore, we concluded that fructose intake in peripubertal rats led to changes in the reproductive system observed both during puberty and adulthood.

Arsenic exposure during prepuberty alters prostate maturation in pubescent rats.

Arsenic is a widely dispersed chemical compound in the environment and has been associated with the development of some diseases and different types of cancer. Little is known about the action of arsenic compounds on prostate development during prepuberty and puberty. This study evaluated prostate morphophysiology after sodium arsenite exposure during prepubertal period in rats. Male Wistar rats at PND23 were randomly distributed into three experimental groups (n = 10/group). The Ctrl group (filtered drinking water); As1 group (0.01 mg/L of NaAsO2); As2 group (10.0 mg/L of NaAsO2) that received the diluted solution in drinking water from PND23 to PND53. Histological and molecular analyzes showed developmental delay in the As1 group and important morphophysiological alterations in As2 group. The results showed that exposure to NaAsO2 during prepuberty compromised structural and functional maturation of the prostate in pubertal rats at both doses evaluated in this study.

Effects of Bauhinia forficata on glycaemia, lipid profile, hepatic glycogen content and oxidative stress in rats exposed to Bisphenol A.

Bisphenol A (BPA) is an abundant raw material applied in the production of daily necessities, such as food cans, baby bottles, electronic and medical equipment. Phytotherapeutic use of plant preparations has long been known for multiple target medicinal uses. The species Bauhinia forficata is widely used as hypoglycemic, anti-inflammatory, antioxidant, diuretic and hypocholesterolemic agent. The aim of this study was to verify the effects of B. forficata extract in association with BPA exposure on serological parameters, hepatic antioxidant status and glycogen store capacity in Wistar rats. B. forficata was able to reduce BPA-induced glucose levels; it also prevented the early glucose elevation in control and BPA-exposed animals after the glucose provocative test. This effect was related to the hepatic glycogen content; while BPA reduced the hepatic glycogen deposits B. forficata treatment contributed to minimize it. BPA and B. forficata singly caused elevation in triacylglycerol and VLDL levels and reduction in cholesterol and LDL concentrations. BPA increased hepatic malondialdehyde levels and reduced catalase activity, thus inducing liver oxidative stress. Conversely, B. forficata treatment reduced malondialdehyde concentration without interfering with catalase activity; this antioxidant capacity is attributed to the flavonoids content (e.g., kaempferol and myricetin). Based on these results, we demonstrated that B. forficata commercial extract has hypoglycemic and antioxidant properties capable of minimizing the effects of BPA. However, it should be considered that the consumption of herbal commercial extract must be judicious to avoid deleterious health effects.

Sleep restriction during peripuberty unbalances sexual hormones and testicular cytokines in rats.

Spermatogenesis and steroidogenesis are not fully established during puberty. Especially during this period, children and adolescents may be chronically sleep deprived due to early school hours and constant exposure to artificial light and interactive activities. We have previously shown that sleep restriction (SR) during peripuberty impairs sperm motility and has consequences on epididymal development in rats. Thus, this study aimed to evaluate the effect of SR during peripuberty on sexual hormones and its impact on testicular tissue. Rats were subjected to 18 h of SR per day for 21 days or were maintained as controls (C) in the same room. The circulating luteinizing hormone levels were decreased in SR rats without changes in the follicle stimulating hormone levels. Plasma and intratesticular testosterone and corticosterone in the SR group were increased in relation to C group. These alterations impair testicular tissue, with decreased IL-1ß, IL-6, and TNFα levels in the testis and diminished seminiferous epithelium height and Sertoli cell number. SR also increased testicular lipid peroxidation with no alteration in antioxidant profiles. There were no significant changes in sperm parameters, seminiferous tubule diameter, histopathology, spermatogenesis kinetics, neutrophil and macrophage recruitment, and IL-10 concentration. Our results show that SR unbalances sexual hormones and testicular cytokines at a critical period of sexual maturation. These changes lead to lipid peroxidation in the testes and negatively influence the testicular tissue, as evidenced by diminished seminiferous epithelium height-with apoptosis of germinative cell-and Sertoli cell number.

Bupropion promotes alterations in the spermatogenesis of mice and congenital malformations in the offspring.

Bupropion hydrochloride (BUP) has been associated with male sexual dysfunction. The aim of this study was to evaluate the effects of BUP on the reproductive function of male mice and to evaluate offspring development. The mice were distributed into BUP group (40mgkg-1) and control group (saline). On Day 35 of treatment the males were placed to mate with females and then killed on Day 46 for evaluation of reproductive function. On Day 18 of pregnancy, pregnant females were killed for evaluation of congenital malformations in the offspring. The BUP group showed a decrease in the Johnsen score (Control, 9.354±0.092; BUP, 7.615±0.147), Sertoli (Control, 5.623±0.184; BUP, 4.215±0.097) and Leydig (Control, 11.430±0.817; BUP, 7.531±0.213) cell counts, testosterone levels (Control, 783.5±154.2ngdL-1; BUP, 201.4±54.8ngdL-1) and sperm production (Control, 2.852±0.211; BUP, 1.988±0.116) and increased morphological alterations of the sperm head (Control, 8.134%; BUP, 10.423%) and tail (Control, 4.96%; BUP, 16.211%). The congenital malformations observed in BUP-derived offspring were: kyphosis (Control, 0.00%; BUP, 5.26%), retroverted rear legs (Control, 14.43%; BUP, 53.68%), incomplete ossification of the supraoccipital and exoccipital (Control, 21.82%; BUP, 86.00%) and sternum (Control, 25.45%; BUP, 82.00%). BUP had toxic effects on testicular function and teratogenic potential.

Can resveratrol attenuate testicular damage in neonatal and adult rats exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin during gestation?

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is considered one of the most toxic dioxins. The effects of TCDD are exerted via binding to the aryl hydrocarbon receptor (AhR). The aim of the present study was to evaluate the possible protective effects of resveratrol, an AhR antagonist, against testicular damage caused by TCDD exposure during pregnancy. Pregnant female Sprague-Dawley rats were divided into four groups: a control group; a group treated with 1µgkg-1, p.o., TCDD on Gestational Day (GD) 15; a group treated with 20µgkg-1, p.o., resveratrol on GD10-21; and a group treated with both TCDD and resveratrol. Rats were weighed and killed, and neonatal testes were collected for histopathological analysis on Postnatal Day (PND) 1. At PND90, adult male rats were killed and the testes collected for histopathological analysis and determination of sperm count. Resveratrol had a protective effect against the effects of TCDD on Sertoli cell number in adult and neonate testes, as well as against the effects of TCDD on abnormal seminiferous tubules in adults. Combined administration of TCDD and resveratrol altered the kinetics of spermatogenesis and the proportion of neonatal testicular compartments compared with the control group In addition, combined TCDD and resveratrol treatment decreased seminiferous tubule diameter in adult male rats compared with the control group. In conclusion, resveratrol may protect against some TCDD-induced testicular damage, but, based on the parameters assessed, the administration of resveratrol and TCDD in combination may result in more severe toxicity than administration of either drug alone.

A High Fat Diet during Adolescence in Male Rats Negatively Programs Reproductive and Metabolic Function Which Is Partially Ameliorated by Exercise.

An interaction between obesity, impaired glucose metabolism and sperm function in adults has been observed but it is not known whether exposure to a diet high in fat during the peri-pubertal period can have longstanding programmed effects on reproductive function and gonadal structure. This study examined metabolic and reproductive function in obese rats programmed by exposure to a high fat (HF) diet during adolescence. The effect of physical training (Ex) in ameliorating this phenotype was also assessed. Thirty-day-old male Wistar rats were fed a HF diet (35% lard w/w) for 30 days then subsequently fed a normal fat diet (NF) for a 40-day recovery period. Control animals were fed a NF diet throughout life. At 70 days of life, animals started a low frequency moderate exercise training that lasted 30 days. Control animals remained sedentary (Se). At 100 days of life, biometric, metabolic and reproductive parameters were evaluated. Animals exposed to HF diet showed greater body weight, glucose intolerance, increased fat tissue deposition, reduced VO2max and reduced energy expenditure. Consumption of the HF diet led to an increase in the number of abnormal seminiferous tubule and a reduction in seminiferous epithelium height and seminiferous tubular diameter, which was reversed by moderate exercise. Compared with the NF-Se group, a high fat diet decreased the number of seminiferous tubules in stages VII-VIII and the NF-Ex group showed an increase in stages XI-XIII. HF-Se and NF-Ex animals showed a decreased number of spermatozoa in the cauda epididymis compared with animals from the NF-Se group. Animals exposed to both treatments (HF and Ex) were similar to all the other groups, thus these alterations induced by HF or Ex alone were partially prevented. Physical training reduced fat pad deposition and restored altered reproductive parameters. HF diet consumption during the peri-pubertal period induces long-term changes on metabolism and the reproductive system, but moderate and low frequency physical training is able to recover adipose tissue deposition and reproductive system alterations induced by high fat diet. This study highlights the importance of a balanced diet and continued physical activity during adolescence, with regard to metabolic and reproductive health.

Low doses of bisphenol A can impair postnatal testicular development directly, without affecting hormonal or oxidative stress levels.

Bisphenol A (BPA) is considered a potent endocrine disruptor, causing changes in the endocrine system due to its oestrogenic activity. Male individuals may be susceptible to endocrine, morphological and physiological alterations during testicular postnatal development. The aim of the present study was to evaluate whether exposure to BPA during the peripubertal period can damage testicular development. To this end, male Wistar rats were treated with BPA via gavage at doses of 20 or 200µgkg-1 on Postnatal Days (PND) 36-66. The control group was treated with Oil+DMSO under the same conditions. On PND 67, rats were killed. The blood was collected for hormonal analysis, the testis for sperm count, oxidative stress, histopathological and immunohistochemical analyses for ki-67 and sperm of the vas deferens for morphological analysis. Both doses of BPA resulted in abnormal sperm morphology and seminiferous tubules, with the highest dose increasing the height of the germinal epithelium and reducing the number of spermatozoa at Stages IX-XIII of spermatogenesis. In conclusion, both doses of BPA administered during the peripubertal period impaired testicular development without any effects on hormone levels (luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone levels) or oxidative stress.

Decreased Implantation Number After In Utero Artificial Insemination Can Reflect an Impairment of Fertility in Adult Male Rats After Exogenous Leptin Exposure.

Leptin is a protein secreted by the adipocytes, which serves as a link between fat and brain. Its main action is to decrease appetite and increase energy expenditure, but it is also involved in the control of different neuroendocrine systems, including gonadal axis. Although the effects of leptin deficiency on reproduction are well recognized, the effect of excess leptin on male reproductive function is not clear. The aim of this study was to evaluate fertility and sperm parameters of male rats exposed to exogenous leptin. A group of adult male rats received exogenous leptin intraperitoneally (30 µg/kg/day) for 42 days, and a control group received only the vehicle during the same period. After the treatment, animals were evaluated for sperm count, sperm motility, and fertility after intrauterine artificial insemination. There was no statistically significant difference between the groups related to sperm production, sperm concentration, and sperm motility. However, fertility evaluation after artificial insemination showed a quantitative decrease in the uterus plus fetuses weight, number of implantation sites, and number of live fetuses. The fertility potential showed a reduction of about 40%, whereas the preimplantation loss rate increased more than 2-fold in leptin-treated animals. In conclusion, leptin administration to nonobese male rats impairs ability of treated animals to generate offspring, since the occurrence of implantation was diminished. So leptin can impair sperm quality, affecting the reproductive capacity.

Sleep restriction in Wistar rats impairs epididymal postnatal development and sperm motility in association with oxidative stress.

Good sleep quality has a direct effect on the activity of the neuroendocrine-reproductive control axis and oxidative stress. Thus, the aim of the present study was to evaluate whether sleep restriction (SR) during the peripubertal period impaired the postnatal development of the epididymis in Wistar rats. After 21 days SR (18h per day), epididymides were collected on Postnatal Day (PND) 62 for evaluation of oxidative stress markers, inflammatory profile, sperm count and histopathological and stereological analyses; in addition, the motility of spermatozoa from the vas deferens was examined. SR significantly increased lipid peroxidation and glutathione levels in the caput and cauda epididymidis, and increased levels of total radical-trapping antioxidant potential in the caput epididymidis only. Neutrophil migration to the caput or corpus epididymidis was decreased by SR, and the size of the luminal compartment in the 2A region and the epithelial compartment in the 5A/B region was also decreased. In these regions, there was an increase in the size of the interstitial compartment. The percentage of immotile spermatozoa was higher in the SR group. In conclusion, SR affects epididymal postnatal development, as well as sperm motility, in association with increased oxidative stress and a decrease in the size of the epithelial compartment in the cauda epididymidis.

Spermatic and testicular damages in rats exposed to ethanol: influence of lipid peroxidation but not testosterone.

Chronic consumption of ethanol causes morphological and physiological changes in the reproductive system of mammals. Vitamin C has an antioxidant role in organisms by neutralizing the ROS (reactive oxygen species) produced by oxidizing agents and this vitamin has an important function in the male reproductive system. The aim of this study was to evaluate whether vitamin C could prevent or attenuate the alterations in the male reproductive system caused by ethanol consumption. To test this hypothesis, male rats were divided into three experimental groups and treated by gavage for 63 days. The ethanol (E) and ethanol+vitamin C (EC) groups received 2 g/kg of ethanol (25%v/v) daily. In addition to ethanol, the EC group received vitamin C at a dose of 100 mg/day, diluted in water. The control group (C) received only the vehicle. On the 64th experimental day, the animals were anesthetized and euthanized, and blood was collected for plasmatic hormonal analysis. The testis, epididymis, vas deferens, and seminal vesicles were removed and weighed. Sperm from the vas deferens was submitted to morphological and motility analysis. The testis and epididymis were used for oxidative stress and histopathological analysis, sperm count, morphometric analysis of the testis, and stereological analysis of the epididymis. The results showed that vitamin C has a protective effect in the testes of adult male rats, entirely normalizing the parameters of sperm count, spermatogenesis kinetics, lipid peroxidation levels, and sperm motility, as well as partially normalizing the histopathological damage in the testis, epididymis, and sperm morphology. Thus, we concluded that lipid peroxidation is a major mechanism by which ethanol affects the testes and sperm, whereas no plasmatic testosterone alterations were found.

Effects of diuron on male rat reproductive organs: a developmental and postnatal study.

This study was performed to determine whether developmental exposure (perinatal and juvenile) to the herbicide diuron exerted adverse effects on adult rat male reproductive system. Pregnant Sprague-Dawley rats received basal diet or diet containing diuron at 500 or 750 ppm from gestational day 12 (GD 12) until the end of lactation period (postnatal day 21, PND 21). After weaning male offspring received basal diet or diet containing diuron until PND 42 (peripubertal age). At PND 90, adult male rats from each experimental group were anesthetized and euthanized for evaluation of body and reproductive organ weights, sperm parameters, plasma testosterone levels, and testicular and epididymal histopathology. Male offspring exposed to diuron at 750 ppm displayed reduced body weight at PND 10, 21, 42, and 90 compared to controls. At PND 90, diuron treatment did not induce significant change in daily sperm production, sperm morphology and motility, and testosterone levels compared to controls. In conclusion, diuron at 750 ppm induced male offspring toxicity but these alterations were not permanent, as evidenced by absence of reproductive-system alterations in adult Sprague Dawley rats.

Can vitamins C and E restore the androgen level and hypersensitivity of the vas deferens in hyperglycemic rats?

Diabetic neuropathy can affect the male reproductive system. The aim of this study was therefore to evaluate whether antioxidant (vitamins C and/or E) treatment could attenuate reproductive dysfunctions in hyperglycemic adult male rats. The animals were randomly assigned to one of four experimental groups: hyperglycemic control (Hy), hyperglycemic + 150 mg/day vitamin C (HyC), hyperglycemic + 100 mg/day vitamin E (HyE) or hyperglycemic + vitamins C and E (HyCE). The normoglycemic group (n = 10) received only the vehicles. The testosterone level and noradrenergic response of the vas deferens were analyzed. Both vitamins significantly decreased the TBARS (thiobarbituric acid reactive species) level in the hyperglycemic groups. There was a significant reduction in the testosterone level in the Hy and HyE groups when compared to the normoglycemic group. However, the testosterone levels were partially recovered in the HyC and HyCE groups. In addition, an increased sensitivity of the α-1 adrenoceptor in the vas deferens of the hyperglycemic control group was observed. Treatment with vitamins partially restored (vitamin E or in combination with vitamin C) or totally (vitamin C alone) this dysfunction. Moreover, the maximum response values to norepinephrine were similar among all groups. Thus, we concluded that vitamin C is more efficient than vitamin E in attenuating the effects of hyperglycemia on the male reproductive system of adult rats.

Acceleration of sperm transit time and reduction of sperm reserves in the epididymis of rats exposed to sibutramine.

Sibutramine is a drug globally used for the treatment of obesity. The aim of this study was to investigate male reproductive disorders caused by sibutramine in adult rats. Wistar rats were treated for 28 consecutive days (gavage) with 10 mg/kg of sibutramine. Control animals received only vehicle (dimethylsulfoxide and saline). The rats were sacrificed for evaluation of body and reproductive organ weights, sperm parameters, hormone levels (luteinizing hormone, follicle-stimulating hormone, and testosterone), testicular and epididymal histopathology, sexual behavior, fertility and in vitro contractility of the epididymal duct. Sibutramine decreased (P < .05) weights of the epididymis and ventral prostate, but not of other reproductive organs. The sperm number and transit time in the epididymal cauda were decreased (P < .001), but the daily sperm production was not altered. Moreover, morphology and sperm motility, histopathology of the testes and epididymis, sexual behavior, fertility, and serum hormone levels were not altered by the treatment. Sibutramine increased the potency of norepinephrine and, per se, increased the mechanical activity of the epididymal duct in vitro. Thus, although sibutramine in these experimental conditions did not interfere with the reproductive process of rats, it provoked acceleration of the sperm transit time and a decrease in the sperm reserves in the epididymal cauda. This alteration is probably related to the sympathomimetic effect of this drug, as shown by the in vitro assays. In humans, use of this drug might present a threat for male fertility because sperm reserves in men are naturally lower than those in rats.

Vitamin C partially attenuates male reproductive deficits in hyperglycemic rats.

BACKGROUND: Hyperglycemia can impair the male reproductive system in experimental animals and in men during reproductive age. Studies have shown that vitamin C has some good effects on male reproductive system, and therefore vitamin C treatment could attenuate the dysfunctions in this system caused by hyperglycemia. Thus, the objective of this work was to evaluate whether vitamin C treatment could attenuate reproductive dysfunctions in hyperglycemic male rats. METHODS: Adult male rats were divided into 3 groups: a normoglycemic (n = 10) and two hyperglycemic (that received a single dose of streptozotocin - 40 mg/kg BW). The two last groups (n = 10 per group) were divided into: hyperglycemic control (Hy) and hyperglycemic + 150 mg of vitamin C (HyC), by gavage during 30 consecutive days. The normoglycemic and hyperglycemic control groups received the vehicle (water). The first day after the treatment, the rats were anesthetized and killed to evaluate oxidative stress biomarkers (TBARS, SOD, GSHt and GSH-Px) in the erythrocytes, body and reproductive organ weights, sperm parameters, plasma hormone levels (FSH, LH and testosterone), testicular and epididymal histo-morphometry and histopathology. RESULTS: Compared with the normoglycemic animals, hyperglycemic control rats showed reduced weight of the body and reproductive organ but testis weight was maintained. It was also observed reduction of testosterone and LH levels, seminiferous tubular diameter, sperm motility and sperm counts in the epididymis. In addition, there was an increase in morphological abnormalities on spermatozoa as well as in oxidative stress level. Vitamin C reduced the oxidative stress level, diminished the number of abnormal sperm, and increased testosterone and LH levels and seminiferous tubular diameter but did not show improvement of sperm motility in relation to the hyperglycemic control group. Hyperglycemia caused a rearrangement in the epididymal tissue components (stroma, ephitelium and lumen) as demonstrated by the stereological analysis results. However, this alteration was partially prevented by vitamin C treatment. CONCLUSIONS: We conclude that vitamin C partially attenuated some male reproductive system dysfunctions in hyperglycemic rats.

Ejaculatory dysfunction in streptozotocin-induced diabetic rats: the role of testosterone.

Hyperglycemic and hypoinsulinemic states caused by diabetes mellitus are usually related to some type of sexual dysfunction, resulting in infertility in humans and experimental models, mostly due to their effects on ejaculatory function. This study aimed to evaluate the possible role of testosterone in the restoration of normal ejaculatory function in diabetic rats. Male Wistar rats were randomly allocated into 3 experimental groups: control, diabetic (streptozotocin), and diabetic with testosterone supplementation (streptozotocin plus testosterone). The following parameters were assessed at the end of the experiment: body weight, circulating testosterone levels, number of spermatozoa ejaculated in the uterus through natural mating, and weight and in vitro isometric contractions of the vas deferens. Diabetic rats showed reduced plasma testosterone levels and ejaculatory dysfunction as observed by a lack in the spermatozoa ejaculated into the uterus of receptive females. In these diabetic rats, no difference was observed in the sensitivity of the vas deferens to norepinephrine, with or without the presence of the cocktail (cocaine plus propranolol). In spite of this, an increased sensitivity to methoxamine through the α1-adrenoceptor was observed. Testosterone supplementation did not restore these parameters to control values.We conclude that, in this experimental model, the lack of testosterone was not directly related to the diabetes-induced ejaculatory dysfunction.

Diet-induced obesity in rats leads to a decrease in sperm motility.

BACKGROUND: Obesity is rapidly becoming a worldwide epidemic that affects children and adults. Some studies have shown a relationship between obesity and infertility, but until now it remains controversial. Thus, the aim of the present study was to investigate the effect of high-fat diet-induced obesity on male reproductive parameters. METHODS: In a first experiment, male Wistar rats were fed a high-fat diet (HFD) or standard chow (SD) for 15, 30 or 45 weeks, after which they were evaluated by adiposity index, serum leptin levels, reproductive organ weights and sperm counts. In a second experiment, rats received HFD or SD only for 15 weeks, long enough to cause obesity. Sexual hormones and sexual behavior were evaluated in these animals, as well as fertility after natural mating. Another group of rats was submitted to motility analysis and fertility evaluation after in utero insemination. RESULTS: After 15, 30 or 45 weeks, HFD-fed animals presented significant increases in obesity index and serum leptin levels. Reproductive organ weights and sperm counts in the testis and epididymis were similar between the two groups at all timepoints studied. Sexual behavior was not altered by the diet regimen, and HFD fertility after natural mating was also similar to SD-fed animals. Intergroup testosterone levels were also comparable, but estradiol levels were increased in HFD rats. Furthermore, sperm quality was reduced in HFD animals as evidenced by their decreased percentage of sperm with progressive movement. This altered motility parameter was followed by a trend toward reduction in fertility potential after artificial in utero insemination. CONCLUSIONS: The results reported herein showed that obesity can affect sperm quality, by reducing sperm motility, without affecting other sperm parameters. The low sperm quality caused a slight reduction in fertility potential, showing that obesity may lead to impairment in male fertility.

Reproductive effects in male rats exposed to diuron.

Diuron is a ureic herbicide considered to have very low toxicity. The present study evaluated several aspects of reproductive toxicity of diuron in adult male rats. Diuron was diluted in corn oil and administered by oral gavage to groups of 18-20 rats at doses of 0, 125 or 250 mg/kg per day for 30 days; the control group received only the corn oil vehicle. At the end of the treatment period, approximately half the animals from each group were assigned to one of two terminal assessment lines: (1) reproductive organ, liver and kidney weights; measurement of diuron concentrations in liver and kidney; plasma testosterone determinations; evaluation of daily sperm production per testis; sperm number and sperm transit time in the epididymis; or (2) sexual behavior assessment during cohabitation with a receptive female; fertility and pregnancy outcome after natural mating; testicular, epididymal, kidney and liver histopathology; sperm morphology. After 30 days of oral diuron treatment, there were no treatment-related changes in body weights, but dose-related diuron residues were detected in the liver of all treated rats and absolute and relative liver weights were increased in both groups. There were no statistically significant differences between the treated and control groups obtained in plasma testosterone concentrations, or in parameters of daily sperm production, sperm reserves in the epididymis, sperm morphology or measured components of male sexual behavior. On the other hand, the number of fetuses in the litters from diuron-treated rats was slightly smaller than litters from control rats. Therefore, although the results did not indicate that diuron exposure resulted in direct male reproductive toxicity in the rat, they suggest that additional studies should be undertaken to investigate the possible effects on fertility and reproductive performance.