Steroidogenic alterations in testes and sera of rats exposed to trichloroethylene (TCE) by inhalation

1. Trichloroethylene (TCE) is an organic unsaturated solvent used in dry cleaning, metal degreasing, thinner for paints/varnishes, anaesthetic agents etc. Human beings are considerably exposed to TCE vapours by inhalation route. 2. TCE has been reported to induce spontaneous abortions and congenital cardiac malformation in occupationally exposed women. However, scanty on-line information is available regarding toxic effects of TCE on male reproductive efficiency in experimental animals. 3. Our earlier observations with TCE inhalation in male rats (376 p.p.m., 4 h/day, 5 days a week) for 12 and 24 weeks using whole body dynamic inhalation chamber consistently showed significant decrease (P<0.05) in total epididymal sperm count and sperm motility. The mating experiments of above TCE inhaled rats with virgin unexposed females showed significantly decreased fertility. 4. These observations prompted us to investigate whether or not primary testicular steroidal precursors (cholesterol and ascorbic acid) and testosterone have any role in TCE induced significantly decreased epididymal sperm count, sperm motility and overall male reproductive inefficiency resulting therefrom. 5. The results indicate significant decrease (P<0.05) in total epididymal sperm count, sperm motility, specific activities of enzymes Glucose 6-p dehydrogenase (G6PDH) and 17 beta hydroxy steroid dehydrogenase (17betaHSD) with concomitant decrease in serum testosterone concentrations in TCE inhaled rats showing reduced male reproductive efficiency. There was net accumulation in total cholesterol contents in testes of TCE exposed rats. 6. The findings in the present study indicate possible impairment of testosterone biosynthesis in TCE inhaled rats after 12 and 24 weeks. These findings also serve in parts to elucidate the mechanism of reproductive inefficiency in TCE exposed rats. The role of testosterone in this phenomenon is being reported for the first time.     

Prenatal di‐n‐butyl phthalate exposure alters reproductive functions at adulthood in male rats

This study was aimed to investigate the reproductive health in adult male rats exposed to di‐n‐butyl phthalate (DBP) during embryonic development. Pregnant rats were injected with DBP and F1 male rats were weaned and on postnatal day 100, used for mating with normal cycling females to assess reproductive performance. After completion of cohabitation period, rats were analyzed for other reproductive end points. Transplacental exposure to DBP significantly decreased fertility in adult male rats. Prenatal exposure to DBP significantly decreased sperm density, number of motile sperms, viable sperms, and hypoosmotic swelling tail coiled sperms with an increase in morphological abnormalities in sperms. Testicular steroidogenic enzyme activity levels and serum testosterone levels were significantly decreased in rats exposed to DBP during embryonic development. In conclusion, transplacental exposure to DBP impairs male reproductive performance by decreasing steroidogenesis and spermatogenesis. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 534–544, 2014.     

Chronic exposure to dibromoacetic acid, a water disinfection byproduct, diminishes primordial follicle populations in the rabbit.

To determine if dibromoacetic acid (DBA) affects ovarian folliculogenesis, four groups of female Dutch-belted rabbits were exposed daily to 0, 1, 5, or 50 mg DBA/kg body weight in drinking water beginning in utero from gestation day 15 throughout life. Functionality of the endocrine axis was assessed by measuring serum concentrations of gonadotropins following an im injection of 10 microg GnRH at 12 (prepubertal; n = 6/dose group) and 24 (postpubertal; n = 10/dose group) weeks of age. A day after GnRH challenge, number of ovulation sites and ovarian weights were determined at necropsy. Left ovaries were processed for histopathology, serially sectioned at 6 microm, and every twelfth section stained with hematoxylin and eosin was evaluated. All healthy follicles were categorized as primordial, primary, small preantral, large preantral, or small antral follicles. The area of each section evaluated was measured and the number of follicles in each category expressed per mm2 unit area. In prepubertal animals, DBA caused a reduction in number of primordial follicles (p < 0.05) and total healthy follicles (p < 0.05) at 50 mg/kg dose level. In adult animals, there were fewer primordial follicles in both the 5 (p < 0.01) and 50 (p = 0.1) mg/kg dose groups. No profound changes in gonadotropin profiles were observed. Although chronic exposure to DBA did not appear to have an effect on late follicular development or ovulation, DBA did reduce the population of primordial follicles. The long-term health consequences of diminished primordial follicles are unknown, but it is very likely that reproductive senescence would occur earlier.     

Fetal testosterone insufficiency and abnormal proliferation of Leydig cells and gonocytes in rats exposed to di(n-butyl) phthalate

Adult male rats previously exposed on gestation days (GD) 12-21 to di(n-butyl) phthalate (DBP) have reproductive tract malformations, particularly agenesis of the epididymis, decreased sperm production, and Leydig cell hyperplasia and adenomas. Although similar effects are produced by the potent androgen receptor (AR) antagonist flutamide and are indicative of disruption of male sexual differentiation via an antiandrogenic mechanism, DBP is not an AR antagonist. The purpose of the study was to determine whether DBP causes pathologic changes and alterations in androgen status in the testis during the prenatal period of male reproductive tract differentiation. Pregnant CD rats were given corn oil, DBP (500 mg/kg/day), or flutamide (100 mg/kg/day) p.o. on GD 12-21. At GD 16-21, DBP caused hyperplasia of Leydig cells, many of which were 3beta-hydroxysteroid dehydrogenase- and/or AR-positive. Focal areas of hyperplasia had increased numbers of Leydig cells positive for proliferating cell nuclear antigen (PCNA). At GD 21, testis atrophy was apparent, seminiferous cords in DBP-exposed fetuses were enlarged and contained multinucleated gonocytes that, unlike controls, were PCNA-positive. DBP, but not flutamide, markedly decreased testicular testosterone levels at GD 18 and 21. Fewer epididymal ducts and reduced AR staining in some ducts were evident with DBP treatment, whereas decreased overall AR staining was seen with flutamide in the presence of mild Leydig cell hyperplasia. Leydig cell proliferation is likely a compensatory mechanism to increase testicular steroidogenesis triggered by testosterone insufficiency. The overall decrease in androgen concentration is not corrected and results in reproductive tract malformations. The multinuclearity and proliferation of gonocytes suggests an underlying Sertoli cell dysfunction.     

Measurement of semen quality,fertility, and reproductive hormones to assess dibromochloropropane (DBCP) effects in live rabbits

Thirty-six sexually mature Dutch rabbits were divided into six equal groups to receive in the drinking water 5 days/week for 10 weeks 0, 0.94, 1.88, 3.75, 7.50, and 15.00 mg of DBCP/kg body wt. General health, body weight, semen quality (four ejaculates per male per week), and libido were measured throughout. Fertility, blood follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone were measured the last week and caude epididymal sperm were examined at sacrifice. There was no effect of DBCP on general health or body weight. There was considerable variation in ejaculate volume, percentage motile sperm, and sperm concentration per milliliter within groups and among weeks. However, between the first 2 weeks and the last 2 weeks of the experiment sperm output had increased by 19% in the three lower DBCP groups and decreased by 16% in the three higher DBCP groups (p < 0.01). The proportion of sperm with abnormal tails also increased as DBCP dosage increased. Fertility was unaffected. FSH was elevated (p < 0.01) in the group receiving 15 mg/kg of DBCP, which is consistent with the impairment of spermatogenesis. Libido, LH, and testosterone levels were not affected. Sperm morphology was the most sensitive indicator of a DBCP effect in the live animal, being affected at a daily oral intake ≥ 1.88 mg DBCP/kg body wt.     

Sub-chronic exposure to dibromoacetic acid, a water disinfection by-product, does not affect gametogenic potential in mice.

Water disinfection by-products, such as dibromoacetic acid (DBA), are formed when drinking water is treated with chlorination, bromination, or ozonation. Epidemiological studies have linked these byproducts to adverse effects in humans such as cancer, developmental defects, and reproductive toxicities. DBA has been shown to produce reproductive toxicity in rodents at relatively high doses. The present study used a mouse model to determine the developmental and reproductive effects of sub-chronic, low-dose exposure to DBA. Pregnant mice (10/dose group) were exposed with DBA in drinking water at 0, 5, or 50 mg/kg/day from gestation day 15 though nursing. Upon weaning at 3 weeks, one group of pups (pre-pubertal group: 7-10 pups of each gender/treatment group) were euthanized and weights of liver, paired kidneys, testes, and ovaries were measured. In the 50 mg dose group, weights of testes and liver in males and weights of liver and kidneys in females were significantly higher (p < 0.05). The remaining pups (15-17 of each gender/dose group) continued to be dosed similarly through adulthood. At 7 weeks of age (neo-pubertal group), animals were euthanized and tissues weighed and processed for evaluation of reproductive organs and gametogenic potential. Except for decreased (p < 0.05) testes and kidney weights in 50 mg dose group males, there were no differences in organ weights. No significant differences were noted between control and dosed animals in daily sperm production, testicular sperm counts, epididymal sperm reserves, morphology of seminiferous epithelium, or ovarian follicle counts.     

Reproductive performance, blood testosterone, lipid peroxidation and seminal plasma biochemistry of rabbits as affected by feeding Acacia saligna under subtropical conditions.

Thirty-two New Zealand White growing rabbits (eight-week old) were used to determine the effect of feeding acacia-based diets on semen characteristics, plasma testosterone, free radicals, seminal plasma enzymes and lipids. Rabbits were randomly assigned to four equal groups. The first group (control) was fed a basal diet only, and the other three groups were fed other three diets, as follows: 80% of basal diet+20% of acacia leaves (low), 60% of basal diet+40% of acacia leaves (medium) and 40% of basal diet+60% of acacia leaves (high), respectively for 32 week. Semen samples were collected throughout the last 12 week of the experimental period. Rabbits fed on different levels of Acacia showed no significant changes in libido (reaction time), ejaculate volume, sperm concentration, packed sperm volume and initial hydrogen ion concentration compared to control. However, low and/or medium levels of Acacia caused significant (P<0.05) increase in total sperm output (TSO), sperm motility (%), total motile sperm per ejaculate (TMS), normal sperm, total functional sperm fraction (TFSF), semen initial fructose, live sperm and plasma testosterone. On the other hand, high level of Acacia did not show any significant change in TSO, sperm motility (%), TMS, initial fructose, TFSF or testosterone, while live and normal sperm decreased. All levels of Acacia caused a significant decrease in the concentrations of thiobarbituric acid-reactive substances (TBARS) and an increase in the activity of glutathione S-transferease. The activities of lactate dehydrogenase (LDH), aminotransferases and phosphatases were significantly increased in seminal plasma of animals fed low or medium levels of Acacia. Seminal plasma total lipid, triglyceride, low density lipoprotein and free fatty acids were significantly (P<0.05) decreased in low or medium levels of Acacia. On the other hand, total cholesterol, percentage cholesterol (out of total lipids) and high density lipoprotein were significantly (P<0.05) increased in seminal plasma of rabbits fed on low or medium levels of Acacia. High level of Acacia did not cause any changes in the previous parameters. It can be concluded that up to 40% Acacia leaves could be used successfully and safely in the diet of rabbits without adversely affecting their reproductive performance under subtropical conditions.     

Toxicologic and Reproductive Effects of Inhaled l,2-Dibromo-3-Chloropropane in Male Rabbits

Toxicologic and Reproductive Effects of Inhaled 1,2-Dibromo-3-ChIoropropanein Male Rabbits. Rao, K.S., Burek, J.D., Murray, F.J., John,J.A., Schwetz, B.A., Beyer, J.E.and Parker, C.M.(l982).Fundam.Appl. Toxicol. 2:241–251. Groups of 10 male New Zealandwhite rabbits were exposed by inhalation to 0, 0.1, 1.0 or 10ppm of 1,2-dibromo-3-chloropropane (DBCP) vapor for 6 hours/day,5 days/week for 14 weeks, except that the 10 ppm group was exposedfor only 8 weeks due to mortality. The semen of rabbits wasevaluated on a weekly basis during the exposure period and atperiodic intervals during a recovery period (32 weeks for allgroups except the 10 ppm groups which was for 38 weeks). Inorder to assess the fertility of the exposed rabbits, each malewas allowed to mate with an unexposed female at the 14th and41st week of the study. Exposure of rabbits to 1 and 10 ppmof DBCP by inhalation produced adverse reproductive effectsas well as decreases in sperm count, motility and viability.Rabbits treated at 1 and 10 ppm had decreased sperm counts betweenthe 8th and 14th weeks of the study. All of the 10 ppm rabbitswere infertile when mated during the 14th week. The effectsof DBCP on spermatogenesis were shown to be essentially reversiblein rabbits exposed to 1 ppm; however, at 10 ppm, recovery wasnot complete under the conditions of the test. Rabbits exposedto 10 ppm had severe testicular alterations as early as 4 weeksinto the study and these progressed to severe testicular atrophyby 8 weeks. Those exposed to 1 ppm for 14 weeks developed moderatetesticular atrophy (approximately 50% reduction in size). Followingthe recovery period, the rabbits in the 10 ppm group had evidenceof partial reversibility of the testicular atrophy. Electronmicroscopic evaluation of testicular tissue confirmed findingsby light microscopy effects and also indicated increased numbersof abnormal sperm within the seminiferous tubules of rabbitsat both the 10 and 1 ppm exposure levels. Those exposed to 0.1ppm had an equivocal increase in abnormal sperm after the 14-weekexposure period but not after the recovery period. Based onthese results 0.1 ppm level of DBCP is considered as a no effectlevel for reproductive parameters.     

Male rats exposed in utero to di(n-butyl) phthalate: Age-related changes in Leydig cell smooth endoplasmic reticulum and testicular testosterone-biosynthesis enzymes/proteins

This study investigated the age-related (i.e., weeks 5, 7, 9, 14 and 17) morphological changes of Leydig cell smooth endoplasmic reticulum (LCs-ER) and testicular testosterone biosynthesis/protein expression in rats in utero exposed to di(n-butyl) phthalate (DBP) (intragastrically; 100 mg/kg/day) on days 12–21 post-conception. Ultrastructural observations revealed the LCs-ER of the DBP group were non-dilated until peri-puberty, and thereafter decreased and disappeared. RT-PCR and Western blotting analyses revealed that StAR and P450scc levels in the DBP group were significantly lower at 5 and 7 weeks compared with the vehicle group but became similar during weeks 9–17. Although 3β-HSD, P450c17, and 17β-HSD levels of mRNA and protein in the DBP group were similar to the vehicle control group at 5 and 7 weeks of age, they were significantly lower during weeks 9–17. In utero DBP exposure results in age-related LCs-ER changes corresponding to reduction of testicular testosterone biosynthesis enzymes/associated proteins.     

Diisobutyl phthalate impairs the androgen-dependent reproductive development of the male rat

Diisobutyl phthalate (DIBP) is the branched isomer of DBP; DBP side chains have a four-carbon backbone (C4), whereas DIBP has its four-carbon alkyl side chains rearranged into a three-carbon backbone (C3) with a methyl branch. Di-n-butyl phthalate (DBP), and several other ortho-phthalate esters with side-chain lengths of C4-C6, are known to disrupt the androgen-dependent sexual differentiation in the male rat. This study was performed to determine whether in utero exposure to DIBP would induce permanent and dose-responsive alterations of male reproductive development. Pregnant Sprague-Dawley rats were administered olive oil (vehicle control), DIBP or DBP, by gavage on gestation Days 12-21, at doses of 125, 250, 500, 625mgDIBP/(kg day) and 500mgDBP/(kg day). DIBP caused no overt maternal toxicity, nor reduced litter size. Male offspring displayed reduced neonatal anogenital distance (Postnatal day 1, PND) at 250mgDIBP/(kg day) and higher doses, and dose-related retention of areolas/nipples (PND 12-14). Preputial separation (onset of puberty) was delayed in male offspring at 500 and 625mgDIBP/(kg day). Hypospadias, cleft prepuce, and undescended testis were observed in males (11-12 or 16-17 weeks old) exposed in utero to 500 and 625mgDIBP/(kg day). Histopathological lesions were also present in adult testes, mainly consisting in seminiferous tubule degeneration. Our results show that DIBP can cause severe and specific adverse effects on the male rat reproductive development, with a pattern similar to that of DBP. However, DIBP appeared slightly less potent than DBP in inducing malformations.     

Effect of in utero and lactational nicotine exposure on the male reproductive tract in peripubertal and adult rats

The objective of this study was to determine the effect of in utero and lactational exposure to nicotine on the male reproductive tract. Dams were randomly assigned to receive saline or nicotine bitartrate (1mg/kg-d s.c.) daily for two weeks prior to mating until weaning (postnatal day 21). Male offspring were sacrificed at 7 (peri-pubertal) and 26 (adult) weeks of age. Nicotine-exposure resulted in retention of spermatids after stage VIII, tubular vacuolation, degeneration of pachytene and round spermatids at stage VII in the testes; and lymphocyte infiltration, germ cell exfoliation, and hypospermia in epididymides, at 7 weeks of age. Nicotine-exposure had no effect on testis or epididymal morphology, daily sperm production, epididymal sperm reserve, sperm viability at 26 weeks of age, and circulating testosterone levels at either age examined. We conclude that maternal nicotine-exposure during pregnancy and lactation can induce transient structural changes in the testis and epididymis of male offspring.     

Dose-dependent alterations in gene expression and testosterone synthesis in the fetal testes of male rats exposed to di (n-butyl) phthalate.

Exposure to di (n-butyl) phthalate (DBP) in utero impairs the development of the male rat reproductive tract. The adverse effects are due in part to a coordinated decrease in expression of genes involved in cholesterol transport and steroidogenesis with a resultant reduction in testosterone production in the fetal testis. To determine the dose-response relationship for the effect of DBP on steroidogenesis in fetal rat testes, pregnant Sprague-Dawley rats received corn oil (vehicle control) or DBP (0.1, 1.0, 10, 50, 100, or 500 mg/kg/day) by gavage daily from gestation day (GD) 12 to 19. Testes were isolated on GD 19, and changes in gene and protein expression were quantified by RT-PCR and Western analysis. Fetal testicular testosterone concentration was determined by radioimmunoassay. DBP exposure resulted in significant dose-dependent reductions in mRNA and protein concentration of scavenger receptor, steroidogenic acute regulatory protein (StAR), cytochrome P450 side-chain cleavage, 3beta-hydroxysteroid dehydrogenase, and cytochrome P450c17. Testicular testosterone was reduced at doses of 50 mg/kg/day and above. Whole-testis expression of peripheral benzodiazepine receptor (PBR) mRNA, which functions with StAR to transport cholesterol across the mitochondrial membrane, was upregulated following exposure to DBP at 500 mg/kg/day. By immunocytochemistry, however, PBR protein was reduced in interstitial cells and also expressed but not reduced in gonocytes. Our results demonstrate a coordinate, dose-dependent reduction in the expression of key genes and proteins involved in cholesterol transport and steroidogenesis and a corresponding reduction in testosterone in fetal testes following maternal exposure to DBP, at dose levels below which adverse effects are detected in the developing male reproductive tract. Alterations in gene and protein expression and testosterone synthesis may serve as sensitive indicators of testicular response to DBP.     

The effects of carbon disulfide on the reproductive system of the male rat

Two experimental protocols were employed to determine the effects of carbon disulfide (CS₂) on the reproductive system of the male rat. In the first experiment, adult Long Evans hooded rats were exposed to 0,350 or 600 ppm CS₂ vapor for 10 weeks (5 h/day, 5 days/week). CS₂ exposure caused no change in reproductive organ weights nor in plasma gonadotropin levels. However, animals exposed to 600 ppm CS₂ had slightly lower epididymal sperm counts and significantly reduced plasma testosterone levels. In order to determine if monitoring hormone levels and sperm status in the same male over time might increase the sensitivity of detecting a toxic reaction, the second protocol was employed. Male rats were exposed to 0 or 600 ppm CS₂. After 0, 1, 4, 7 and 10 weeks of exposure, males were observed for mating behavior, and ejaculated sperm count and plasma hormone levels were determined. Animals exposed to 600 ppm CS₂ had significantly shorter times to mount and to ejaculate and decreased ejaculated sperm counts. Plasma gonadotropin levels were similar in both groups while plasma testosterone levels were marginally depressed in CS₂-exposed animals in the early weeks. These data indicate that CS₂ is a toxin of the male reproductive system resulting in abnormal coital behavior and decreased sperm counts. The second experimental protocol proves to be a sensitive method for assessing adverse effects in the male reproductive system.     

Protective effects of tripterygium glycoside-loaded solid lipid nanoparticles on male reproductive toxicity in rats

The protective effects of tripterygium glycoside-loaded solid lipid nanoparticles (TG-SLNs) on male reproductive toxicity were investigated in rats. Thirty-six male Sprague-Dawley rats were randomly divided into three groups of 12: control group, tripterygium glycoside (TG) group, and TG-SLN group. After the animals had been orally administered with the substances for 28 consecutive days, their sperm count and sperm motility, organ coefficients, serum testosterone levels, testicular ultrastructure, and reproductive ability were observed. The results showed that the sperm motility rate in the TG group was only 3%, whereas the rates in the TG-SLN and control groups were 33% and 71%, respectively. Compared with those in the control group, the motion counts of path velocity, track speed, progressive velocity, straightness, linearity, beat cross frequency, amplitude of lateral head displacement, and sperm concentrations in the TG-SLN group were not significantly different while those in the TG group significantly decreased (p < 0.01). TG-SLNs did not cause testicular atrophy and instead maintained normal serum testosterone levels. The effect of TG-SLNs on the testicular ultrastructure was very evident; the morphologies of Sertoli, spermatogonial, mitochondrial, and sperm cells were normal. In terms of reproductive ability, one rat (17%) from the TG-SLN group and five rats (83%) from the control group became pregnant, whereas none of the rats from the TG group became pregnant. These data indicate that TG-SLNs have potentially protective effects on male reproductive toxicity in rats.     

Protective role of lycopene on cisplatin-induced changes in sperm characteristics, testicular damage and oxidative stress in rats

The aim of this study was to investigate the possible protective role of lycopene on cisplatin (CP)-induced spermiotoxicity using quantitative, biochemical and histopathological approaches. Adult male Sprague-Dawley rats were randomly divided into four groups. The control group received physiological saline; animals in cisplatin group received only cisplatin; pre-treatment group received a 10-day of lycopene before administration of cisplatin while animals in post-treatment group received a 5-day of lycopene following administration of cisplatin. Cisplatin (7 mg kg(-1)) was intraperitoneally (i.p.) injected as a single dose and lycopene (4 mg kg(-1)) was administered by gavage in corn oil. Traits of reproductive organs; sperm characteristics, testicular histological findings, plasma testosterone levels and the testicular tissue oxidative status were determined. Administration of cisplatin to rats decreased sperm concentration (p < 0.05) and sperm motility (p < 0.001), increased total abnormal sperm rates (p < 0.05) as compared with the control group. While a marked normalization was achieved only in sperm concentration with lycopene in pre-treatment group, significant normalizations were achieved in the sperm concentration, sperm motility, total abnormal sperm rates in post-treatment group. No significant differences in levels of testosterone were observed among all groups. An increase in testes malondialdehyde concentrations (p < 0.05) and glutathione peroxidase activities (p < 0.001) were detected while significant decreases in glutathione levels (p < 0.001) in cisplatin alone group when compared to control group. While pre-treatment with lycopene restoring only malondialdehyde concentrations, its post-treatment caused normalization in both malondialdehyde and glutathione levels when compared with the cisplatin alone group. On the other hand, significant increases were determined in GSH-Px activities in all experimental groups when compared with the control group. Although the mechanism is not clear, the results from this experimental study suggest that the lycopene have a possible protective effect against cisplatin-induced spermiotoxicity, effect of giving lycopene after cisplatin being superior to the giving it before cisplatin.     

Effects of polychlorinated biphenyls in CD-1 mice: reproductive toxicity and intergenerational transmission

Several studies indicate that in utero and perinatal exposure to polychlorinated biphenyls (PCBs) induces adverse reproductive effects, but it remains unclear whether such effects may be transmitted to subsequent generations. We therefore investigated the association between maternal exposure to PCBs and reproductive health in male and female offspring over three generations. Mouse dams were fed 0, 1, 10, and 100 μg/kg/day of a PCB mixture (101 + 118) during pregnancy and lactation. PCB levels were measured in the tissues of both dams and offspring. PCB concentrations at all doses investigated were greater in the offspring than in the dams (p ≤ 0.0001) confirming that the progeny were exposed as a result of maternal exposure. In F1 offspring, exposure to PCBs resulted in reductions in (1) testis weight (p ≤ 0.05) and seminiferous tubule diameter (p ≤ 0.05), (2) sperm viability (p ≤ 0.0001) and developmental capacity (p ≤ 0.05), (3) ovary weight (p ≤ 0.05), (4) oocyte developmental capacity (p ≤ 0.05), and (5) increased follicular atresia (p ≤ 0.0001). In females, adverse effects were observed only in the F1 animals. In contrast, male offspring exhibited reduced sperm viability and altered seminiferous tubule distribution up to the third generation, showing intergenerational transmission. In summary, our data indicate that exposure to PCBs at the time of gonadal sex determination perturbed, significantly, the reproductive physiology of male and female offspring in adulthood. Furthermore, male reproductive deficiencies may be observed in at least two further generations. These findings have significant implications for reproductive health and fertility of animals and humans.     

Pre- and postnatal toxicity of the commercial glyphosate formulation in Wistar rats

Glyphosate is the active ingredient and polyoxyethyleneamine is the surfactant present in the herbicide Roundup formulation commercialized in Brazil. The aim of this study was to assess the reproductive effects of glyphosate-Roundup on male and female offspring of Wistar rats exposed during pregnancy and lactation. Dams were treated orally with water or 50, 150 or 450 mg/kg glyphosate during pregnancy (21-23 days) and lactation (21 days). These doses do not correspond to human exposure levels. The results showed that glyphosate-Roundup did not induce maternal toxicity but induced adverse reproductive effects on male offspring rats: a decrease in sperm number per epididymis tail and in daily sperm production during adulthood, an increase in the percentage of abnormal sperms and a dose-related decrease in the serum testosterone level at puberty, and signs of individual spermatid degeneration during both periods. There was only a vaginal canal-opening delay in the exposed female offspring. These findings suggest that in utero and lactational exposure to glyphosate-Roundup may induce significant adverse effects on the reproductive system of male Wistar rats at puberty and during adulthood.     

Pre and postnatal exposure to endosulfan in Wistar rats

The possible reproductive adverse effects of the pesticide endosulfan on male offspring rats exposed in utero and during lactation were investigated. Dams were treated orally with 0, 0.5 or 1.5 mg of endosulfan/kg 21 days prior to mating, during the mating, pregnancy and lactation. Maternal and reproductive outcome data and male sexual development landmarks (testis descent and preputial separation) were assessed. Reproductive endpoints of the male offspring were examined at adulthood: sex organ weights, daily sperm production, spermatid number, sperm transit, sperm morphology and testosterone level. No signs of maternal toxicity were detected at the dose levels tested. Sexual development landmarks were also unaffected. Moreover, with the exception of a significant increase in the relative epididymis weight seen in the group treated with the lowest dose, we have not found any statistically significant adverse effect in the reproductive endpoints investigated at adulthood. The results of the present study indicate that pre and postnatal exposure to low doses of endosulfan (0.5 and 1.5 mg/kg) do not induce significant adverse effects in the reproductive system of male offspring Wistar rats at adulthood.     

Reproductive toxicity of 1-bromopropane, a newly introduced alternative to ozone layer depleting solvents, in male rats.

1-Bromopropane has been newly introduced as an alternative to ozone-depleting solvents. We aimed to clarify its dose-dependent reproductive toxicity in male rats. Thirty-six Wistar male rats were randomly divided into 4 groups of 9. The groups were exposed to 200, 400, or 800 ppm 1-bromopropane or only fresh air, 8 h per day for 12 weeks. Epididymal sperm indices were evaluated after a 12-week exposure. The testes, epididymides, seminal vesicle, prostate, and other organs were weighed and examined histopathologically. Spermatogenic cells, in stage VII seminiferous tubules, and retained spermatids, at the basal region of stages IX-XI seminiferous epithelium, were counted. Plasma testosterone levels were measured by radioimmunoassay. The testicular weight did not significantly change, but the weight of epididymides, seminal vesicle, and prostate dose-dependently decreased. The weight of seminal vesicle decreased significantly at the lowest concentration of 200-ppm and over. 1-Bromopropane induced a dose-dependent decrease in the epididymal sperm count and in motility, as well as an increase in tailless sperm and sperm with an immature head shape. The spermatogonia, preleptotene spermatocytes, pachytene spermatocytes, and round spermatids did not decrease significantly at stage VII. Retained, elongated spermatids near the basement membrane at the postspermiation stages IX-XI increased dose-dependently. Plasma testosterone levels significantly decreased at the 800-ppm dosage. 1-Bromopropane caused failure of spermiation. Its reproductive toxicity is different from that of 2-bromopropane, which specifically impairs spermatogonia. Thus, this solvent may have serious reproductive toxic effects in men, and should be used very cautiously in the workplace.