Reproductive Function In Male Offspring Research Articles

Prenatal exposure to Di(2-ethylhexyl) phthalate and high-fat diet synergistically disrupts gonadal function in male mice†.

Prenatal exposure to Di (2-ethylhexyl) phthalate (DEHP) impairs the reproductive system and causes fertility defects in male offspring. Additionally, high-fat (HF) diet is a risk factor for reproductive disorders in males. In this study, we tested the hypothesis that prenatal exposure to a physiologically relevant dose of DEHP in conjunction with HF diet synergistically impacts reproductive function and fertility in male offspring. Female mice were fed a control or HF diet 7days prior to mating and until their litters were weaned on postnatal day 21. Pregnant dams were exposed to DEHP or vehicle from gestational day 10.5 until birth. The male offspring's gross phenotype, sperm quality, serum hormonal levels, testicular histopathology, and testicular gene expression pattern were analyzed. Male mice born to dams exposed to DEHP + HF had smaller testes, epididymides, and shorter anogenital distance compared with those exposed to HF or DEHP alone. DEHP + HF mice had lower sperm concentration and motility compared with DEHP mice. Moreover, DEHP + HF mice had more apoptotic germ cells, fewer Leydig cells, and lower serum testosterone levels than DEHP mice. Furthermore, testicular mRNA expression of Dnmt1 and Dnmt3a was two to eight-fold higher than in DEHP mice by qPCR, suggesting that maternal HF diet and prenatal DEHP exposure additively impact gonadal function by altering the degree of DNA methylation in the testis. These results suggest that the combined exposure to DEHP and high-fat synergistically impairs reproductive function in male offspring, greater than exposure to DEHP or HF dietalone.

Impact of bisphenol-A on the spliceosome and meiosis of sperm in the testis of adolescent mice

BackgroundBisphenol-A (BPA) has estrogenic activity and adversely affects humans and animals' reproductive systems and functions. There has been a disagreement with the safety of BPA exposure at Tolerable daily intake (TDI) (0.05 mg/kg/d) value and non-observed adverse effect level (5 mg/kg/d). The current study investigated the effects of BPA exposure at various doses starting from Tolerable daily intake (0.05 mg/kg/d) to the lowest observed adverse effect level (50 mg/kg/d) on the testis development in male mice offspring. The BPA exposure lasted for 63 days from pregnancy day 0 of the dams to post-natal day (PND) 45 of the offspring.ResultsThe results showed that BPA exposure significantly increased testis (BPA ≥ 20 mg/kg/d) and serum (BPA ≥ 10 mg/kg/d) BPA contents of PND 45 mice. The spermatogenic cells became loose, and the lumen of seminiferous tubules enlarged when BPA exposure at 0.05 mg/kg/d TDI. BPA exposure at a low dose (0.05 mg/kg/d) significantly reduced the expression of Scp3 proteins and elevated sperm abnormality. The significant decrease in Scp3 suggested that BPA inhibits the transformation of spermatogonia into spermatozoa in the testis. The RNA-seq proved that the spliceosome was significantly inhibited in the testes of mice exposed to BPA. According to the RT-qPCR, BPA exposure significantly reduced the expression of Snrpc (BPA ≥ 20 mg/kg/d) and Hnrnpu (BPA ≥ 0.5 mg/kg/d).ConclusionsThis study indicated that long-term BPA exposure at Tolerable daily intake (0.05 mg/kg/d) is not safe because low-dose long-term exposure to BPA inhibits spermatogonial meiosis in mice testis impairs reproductive function in male offspring.

Особливості розвитку репродуктивної системи щурів нащадків чоловічої статі, що народжені від батька, який до спаровування отримував фітоестрогени

The purpose of the study was the research of the influence of rats father's excessive consumption of phytoestrogens on somato-sexual development and reproductive function of male offspring. Materials and methods. Male parents were fed with a mixture of phytoestrogens before mating with intact females at a dose of 20 mg/kg of body weight for 30 days. In reproductive animals, reproductive function was studied for such characteristics as sexual behavior, fertility, spermogram, the mass of androgen-dependent organs was determined, and the level of sex hormones was determined. Experimental parents were divided into two groups: 1) intact, 2) males who received excess phytoestrogens. After the birth of male offspring from these parents, their reproductive system was examined. Results and discussion. Prolonged administration of phytoestrogens to mature male parents (parents) causes absolute and relative hyperestrogenism (five-fold increase in E2 and vice versa reduction of T/E2 three-fold), which leads to a decrease in copulatory activity (reduction of the number of nurseries and intromissions by 28%), violation of spermatogenesis (reduction of sperm concentration by 39%, doubling the proportion of abnormal forms), at the same time does not affect the reproductive potential of male who were born to fathers who received an excess consumption of phytoestrogens. The presence of excess compounds with estrogenic activity in the diet of adult males in the preconsumption period leads to the birth of male offspring, which have reduced testosterone levels (25%) in the critical period of sexual differentiation of the brain (5 days of life). Descendants of the male sex of the phytoestrogenized father have a normal course of somatic development but are characterized by impaired sexual development (less anogenital distance by 13%) and delayed lowering of the testicles into the scrotum, lower body weight in adulthood (28.2% in 150 day rats). Reproductive function of the offspring of phytoestrogenized father is characterized by differences in sexual behavior: less copulatory activity – 50%, less number intromission, the number of males with ejaculation is 10%; delayed sexual reactions; and lower reproductive potential (two-fold reduction of the integrated indicator of potential fertility of animals). Decreased reproductive potential of the offspring, who were born to fathers who received an excess consumption of phytoestrogens, occurs due to a decrease in the proportion of effective fertilization (pregnant females among those fertilized only 60%), indicating negative changes in sperm, the development of which, starting from the stage of spermatocytes, occurred in conditions of absolute and relative hyperestrogenism. Conclusion. The male who were born to fathers who received an excess consumption of phytoestrogens, have complications in the functioning of the reproductive system

Effects of prenatal chlorocholine chloride exposure on pubertal development and reproduction of male offspring in rats

Chlorocholine chloride (CCC) promote plant growth as a regulator. Emerging evidence by our group showed that CCC might restrain the puberty onset and impair the reproductive functions in male rats through HPT axis. In this study, we further investigated the effects of prenatal CCC exposure on pubertal development, reproduction of male offspring in rats and explored the underlying mechanisms. The results showed that CCC of 137.5 and 200 mg/kg bw/day delayed the age of preputial separation (PPS), decreased the sperm motility of male offspring. PP1γ2 which is an essential protein in spermatogenesis reduced in 137.5 and 200 mg/kg bw/day groups. Crucial hormones involved in hypothalamic-puititary-testicular (HPT) axis decreased at postnatal day (PND) 30. It was indicated that CCC exposure in pregnancy might disturb the pubertal development, reproductive functions of male offspring through HPT axis and disturb the sperm motility through PP1γ2.

Zearalenone affects reproductive functions of male offspring via transgenerational cytotoxicity on spermatogonia in mouse

Previous studies have demonstrated that Zearalenone (ZEA) affects not only maternal reproductive function but also that of the offspring. However, the transgenerational toxic effects of ZEA on the spermatogonia of male F1 mice are not clear. The present study was thus designed to determine whether the fertility of male F1 mice was affected following exposure of F0 pregnant mice to ZEA. In present study, 32 pregnant female mice were divided into 4 groups and exposed to ZEA of 0, 2.5 and 5.0 mg/kg, respectively, and the testis development and reproductive performance of 96 male F1 mice were analyzed. The results demonstrated that the F0 pregnant mice treated with ZEA resulted in increased anogenital distances in the newborn male F1 mice. Moreover, ZEA caused abnormal vacuole structures and loose connections in the testes of male F1 offspring, compared with the controls. Further ultramicrostructural analysis showed that the mitochondria appeared to be vacuolated with ablated membranes and cristae, and this was accompanied by the presence of large lipid droplets in the spermatogonia. Further, the semen quality and sperm counts declined significantly, and increased malformation rates and decreased testosterone levels were observed in the male F1 offspring from experimental groups. Our results reveal the toxic effects of ZEA on F0 pregnant mice is transgenerational, and affects the fertility of male F1 mice by damaging the spermatogonial cells. This offers a new viewpoint of ZEA-induced reproductive toxicity in male animals and provides a new potential direction for the treatment and prevention of ZEA-induced cytotoxicity.

The association between in-utero exposure to stressful life events during pregnancy and male reproductive function in a cohort of 20-year-old offspring: The Raine Study.

Is exposure to gestational stress in the critical time window for the normal differentiation and growth of male reproductive tissue associated with male reproductive function in offspring in later life? Exposure to stressful life events (SLEs) in early, but not late gestation, are associated with reduced adult male reproductive function, consistent with the hypothesis that events during early prenatal life programme adult male reproductive function. Animal studies suggest that gestational stress may impact on the reproductive function of male offspring, but human evidence is sparse. Using a prospective longitudinal cohort, we examined the association between number and type of maternal stressors during pregnancy in both early and late gestation and reproductive function in 643 male Generation 2 (offspring) at age 20 years. Mothers and their male Generation 2 (offspring) from The Raine Study participated. Mothers prospectively reported SLEs during pregnancy recorded at gestational weeks 18 and 34 using a standardized 10-point questionnaire. The 643 male Generation 2 (offspring) underwent testicular ultrasound examination and semen analysis and provided serum for reproductive hormone analysis. Multivariate linear regression analysis was used to examine associations. Of 643 recruited males, 407 (63%) were exposed to at least one SLE in early gestation. Fewer SLEs were reported in late gestation (n = 343, 53%). Maternal SLE exposure in early gestation was negatively associated with total sperm count (β = -0.31, 95% CI -0.58; -0.03), number of progressive motile sperm (β = -0.15, 95% CI -0.31; 0.00) and morning serum testosterone concentration (β = -0.04, 95% CI -0.09; -0.00). No similar effects of maternal SLE exposure in late pregnancy were detected. The large sample size and an objective detailed direct assessment of adult male reproductive function with strict external quality control for sperm quality, as well as detailed prospectively collected information on prenatal SLEs in two distinct time windows of pregnancy reported by the women in early and late gestation along with other risk factors, imply minimal possibility of recall, information bias and selection bias. When assessing our results, we adjusted for a priori chosen confounders, but residual confounding or confounding by factors unbeknown to us cannot be ruled out. It is not possible to measure how SLEs impacted differently on the mother's experience or perception of stress. Resilience (coping) gradients may alter cortisol levels and thus modify the associations we observed and the mothers' own perception of stress severity may have provided a more precise estimate of her exposure. Our findings suggest that exposure to SLEs in early, but not late gestation, are associated with reduced adult male reproductive function. Improved support for women with exposure to SLEs during pregnancy, particularly during the first trimester, may improve the reproductive health of their male offspring in later life. Intervention studies of improved pregnancy support could provide more insight into this association and more information is needed about the potential specific epigenetic mechanisms underlying this association. The male fertility sub-study was funded by NHMRC Grant 634 457. The core management of the Raine Study is funded by University of Western Australia, Curtin University, Telethon Kids Institute, Women and Infants Research Foundation, Edith Cowan University, Murdoch University, The University of Notre Dame Australia and Raine Medical Research foundation. Dr Bräuner's salary was supported by Læge Sofus Carl Emil Friis og Hustru Olga Doris Friis foundation in Denmark. All authors declare no competing interests. N/A.

Exposure to allethrin-based mosquito coil smoke during gestation and postnatal development affects reproductive function in male offspring of rat

The threat of zika virus looms throughout the world and the use of allethrin-based mosquito coils to prevent mosquito bites during and postpregnancy is on the rise. The aim of this study was to analyze the toxic effects of exposure to allethrin-based mosquito coil smoke in rats under conditions that reflect human settings. Pregnant female rats were exposed to mosquito coil smoke and same was continued to the male pups up to 111 days postparturition (21-day weaning plus up to 90 days postweaning). Increased oxidative stress, distorted antioxidant enzyme status, downregulation of genes involved in spermatogenesis, sperm maturation and steroidogenesis was observed. Daily sperm production, total sperm count and acrosome reaction was compromised. Results of our study indicate the toxic effects of exposure to allethrin-based mosquito coil smoke in male offspring and calls for preventing mosquito coil use during pregnancy and postnatal development. Community-based programs that will encourage general population to use classical methods such as use of mosquito nets, keeping the surroundings clean and use of natural mosquito repellents should be conducted.

Gestational and lactational exposure to bisphenol AF in maternal rats increases testosterone levels in 23-day-old male offspring

During prenatal and postnatal development, exposure to environmental chemicals with estrogenic activity, such as bisphenol AF (BPAF), may result in reproductive disorders. Currently, the mechanisms behind such disorders in male offspring induced by gestational and lactational exposure to BPAF remain poorly understood. Here, female rats from gestational day (GD) 3–19 were exposed to 100 mg BPAF/kg/day by oral gavage. On the day of birth (postnatal day (PD) 0), cross-fostering took place between treated and control litters, and cross-fostered mother rats were given BPAF 100 mg/kg/day during the postnatal period (PD 3 to PD 19). HPLC-MS/MS analysis showed that BPAF was transferred via cord blood and lactation, finally bio-accumulating in the offspring testes. Pups exposed to BPAF both prenatally and postnatally showed a significant increase in testis testosterone levels compared with that of the control, while all pups exposed to BPAF showed a significant decrease in testis inhibin B (INHB) levels. Compared with the control, RNA-seq revealed that 279 genes were significantly differentially expressed in the testes of pups exposed to BPAF both prenatally and postnatally, including genes involved in cell differentiation and meiosis. These results indicate that gestational and lactational exposure to BPAF in the mother can impair reproductive function in male offspring.

Maternal hyperglycemia at different stages of gestation and its effects on male reproductive functions in rats.

The critical period during which maternal hyperglycemia predisposes offspring to develop reproductive disorders in adult life is not known. The relationship between maternal hyperglycemia at different stages and reproductive functions of male offspring was investigated. A single intraperitoneal injection of alloxan (90 mg/kg body weight) was administered at gestation days (GD) 1, 8 and 15. Animals were subsequently given 10% glucose solution daily as drinking water until parturition. All male pups were sacrificed on the 63rd day of postnatal life. Birth weight, anogenital distance index (AGDi), testes descent day, preputial separation day, sperm profile, serum testosterone, luteinizing hormone and follicle-stimulating hormone levels and the histology of the testis were assessed. Data significance test was based on 95% confidence interval. GD1 pups showed a significant increase in mean birth weight, whereas GD8 pups and GD15 pups had significantly reduced birth weight as compared with control. AGDi was significantly increased in GD8 and GD15 pups. Testes descent and preputial separation in all the experimental groups were significantly earlier. There was a significant reduction in sperm count and viability in GD8 offspring. Sperm motility was reduced in all test groups. Testosterone level was reduced in all test groups. Histology of the testis showed varying degrees of pathologies. It was deduced from this study that maternal hyperglycemia caused alterations in reproductive functions in male offspring of Wistar rats irrespective of the period of gestation involved, although GD8 pups were most severely affected.

Impact of gestational diabetes and lactational insulin replacement on structure and secretory function of offspring rat ventral prostate

Clinical and experimental studies have shown that exposure to adverse conditions during the critical stages of embryonic, fetal or neonatal development lead to a significantly increased risk of later disease. Diabetes during pregnancy has been linked to increased risk of obesity and diabetes in offspring. Here, we investigated whether mild gestational diabetes mellitus (GDM) followed or not by maternal insulin replacement affects the ventral prostate (VP) structure and function in male offspring at puberty and adulthood. Pregnant rats were divided into the following 3 groups: control (CT); streptozotocin (STZ)-induced diabetes (D); and D plus insulin replacement during lactation (GDI). The male offspring from different groups were euthanized at postnatal day (PND) 60 and 120. Biometrical parameters, hormonal levels and prostates were evaluated. Mild-GDM promoted reduction in the glandular parenchyma and increased collagen deposition. Insulin replacement during lactation restored the VP morphology. Most importantly, mild-GDM decreased the androgen-induced secretory function as determined by prostatein expression, and insulin replacement reversed this effect. Our results demonstrated that mild GDM impairs VP parenchyma maturation, which is associated with an increase in the fibromuscular stroma compartment. Functionally, the reduction in the VP parenchyma decreases the glandular secretory activity as demonstrated by low expression of prostatein, a potent immunosuppressor factor that protects sperm from immunologic damage into the feminine reproductive tract. This change could lead to impairment of reproductive function in male offspring from diabetic mothers. Maternal insulin replacement during the weaning period apparently restores the prostate function in male offspring.

Фітоестрогенізація самців-щурів для соматостатевого розвитку та фертильності їхніх нащадків

The effect of phytoestrogen-rich diet administered to male rats in a dose 20 mg/kg of body weight for 30 days with the mixture of phytoestrogens on reproductive function of male offspring and the effect of additional phytoestrogenization during milk feeding have been investigated. It was shown that male phytoestrogenization leads to feminization of the offsprings. Specifically, at birth, the ano-genital distance in males was less than that measured in control rats: (2.7 +/- 0.1) vs (3.1 +/- 0.0) mm (P < 0.05). This and additional phytoestrogenization of newborn rats during milk feeding inhibit their somatic and sexual development, weakening sexual activity in adults and reducing fertility at the expense of dectreased fertilizing capacity of sperm. A possible mechanism for the observed effects may be a reduction of relative androgenization due to increased of estradiol concentration by 3-4 times. Analysis of the data revealed a significant impact of phytoestrogens in father's diet on reproductive function of their offsprings under conditions of additional phytoestrogenization after birth.

Foetal and postnatal exposure to high temperatures alter growth pattern but do not modify reproductive function in male rabbits

Purpose: The ‘foetal origin hypothesis’ postulates that a number of organ structures and associated functions undergo programming during embryonic and foetal life and the neonatal period, which determines the set point of physiological and metabolic responses that carry into adulthood. We evaluate the relationship between high environmental temperatures and the reproductive function of male offspring to determine whether pregnant mammals and their infants are potentially vulnerable to the effects of climate change.Methods: Rabbit pups were exposed to high temperatures during gestation and lactation. Results: Foetal and postnatal exposure to high temperatures did not alter semen characteristics and was associated with a similar fertility rate and number of pups born. Moreover, males showed reduced rate of maturing and carcass traits at adulthood.Conclusion: Our findings suggest that male exposure during the foetal period to high temperatures did not affect sperm quality but permitted an adaptive phenotypic plasticity of growth in adulthood.

Long-term Effects of Perinatal Androgenization on Reproductive Parameters of Male Rat Offspring Androgenization and Male Rat Reproduction

It is known that during sex differentiation, fetal androgens are critical determinants of the male phenotype. Although testosterone is necessary for normal development of male sexual behavior, perinatal androgen treatment can result in disruption of normal male sexual reproduction. Pregnant Wistar rats were administered either corn oil (vehicle) or testosterone propionate at 0.2 mg/kg from gestational day 12 until the end of lactation and the reproductive function of male offspring was evaluated at 90 (adulthood) and 270 (middle age) days of age. Perinatal androgenization in the rat provoked a reduction in sperm production and reserves in adulthood that did not affect fertility and did not persist at more advanced ages, as shown by the results at post-natal day 270. If perinatal androgenization promotes similar effects in humans of reproductive age, the results of the present work can impact male reproduction health, given the less efficient spermatogenesis and lower sperm reserves in the human epididymis, compared to rodents.

Evaluation of the testicular toxicity of prenatal exposure to bisphenol A based on microarray analysis combined with MeSH annotation

Bisphenol A (BPA) is known to be an endocrine disruptor that affects the development of reproductive system. The aim of the present study was to investigate a group of testicular genes dysregulated by prenatal exposure to BPA. Pregnant ICR mice were treated with BPA by subcutaneous administration on days 7 and 14 of pregnancy. Tissue and blood samples were collected from 6-week-old male offspring. Testes were subjected to gene expression analysis using a testis-specific microarray (Testis2), consisting of 2,482 mouse cDNA clones annotated with Medical Subject Headings (MeSH) terms indicative of testicular components and functions. To interpret the microarray data, we used the MeSH terms significantly associated with the altered genes. As a result, MeSH terms related to androgens and Sertoli cells were extracted in BPA-treated groups. Among the genes related to Sertoli cells, downregulation of Msi1h, Ncoa1, Nid1, Hspb2, and Gata6 were detected in the testis of mice treated with BPA (twice administered 50 mg/kg). The MeSH terms associated with this group of genes may provide useful means to interpret the testicular toxicity of BPA. This article concludes that prenatal BPA exposure downregulates expression of genes associated with Sertoli cell function and affects the reproductive function of male offspring. Additionally, a method using MeSH to extract a group of genes was useful for predicting the testicular and reproductive toxicity of prenatal BPA exposure.

Effects of fetal exposure to carbon nanoparticles on reproductive function in male offspring

To investigate the effects of fetal nanoparticle exposure on reproductive function in male mice offspring. Animal study. Academic research laboratory. Forty pregnant ICR mice and 120 male offspring. Two hundred microg of 14-nm carbon nanoparticles was administered intratracheally on days 7 and 14 of gestation, and reproductive function of male offspring was determined at ages 5, 10, and 15 weeks after birth. Maternal and fetal growth, histologic changes in the testes, and daily sperm production (DSP). Histologic examination showed partial vacuolation of seminiferous tubules. and cellular adhesion of seminiferous epithelia was reduced at all three ages. In addition, DSP was significantly decreased in fetal carbon nanoparticle-exposed mice. The DSP in the fetal carbon nanoparticle-exposed mice decreased by 47% at the age of 5 weeks, by 34% at the age of 10 weeks, and by 32% at the age of 15 weeks. On the other hand, nanoparticle administration had no marked effect on body weight, testicle weight, epididymis weight, or serum testosterone concentration. These findings suggest that fetal nanoparticle exposure affects the reproductive function of male offspring. In the future, it would be necessary to clarify the onset mechanisms of nanoparticle-induced male reproductive disorders.

Maternal Corticosterone Further Reduces the Reproductive Function of Male Offspring Hatched from Eggs Laid by Quail Hens Selected for Exaggerated Adrenocortical Stress Responsiveness

Activation of the hypothalamic-pituitary-adrenal (HPA) axis can depress the hypothalamic-pituitary-testicular axis. Male quail cloacal gland (CG) size and foam production shows androgen dependency, and males selected for exaggerated [high stress (HS)] rather than reduced [low stress (LS)] plasma corticosterone (B) stress response exhibit reduced CG and testes development. High stress hens also deposit more B into egg yolks than LS ones, and quail hens given B produce chicks that have a reduced growth rate and adults with heightened HPA responsiveness. Herein, we gave LS and HS hens no B [empty implants, control (CON)] or B-filled implants and assessed the reproductive performances of these hens and their male offspring. Mortality was similarly elevated in LS and HS B-treated hens, but only HS B-implanted hens showed reduced egg production. In male offspring, CG volume (CVOL), intensity of CG foam production (CFP), and the proportion of individuals that produced CG foam were measured from 4 to 11 wk of age. At 6 wk, BW, and at 15 wk, BW, testes weight (TWT), and TWT relative to BW were also determined. Hen treatments did not affect male chick CVOL at 4 wk, but CVOL differed thereafter as follows: LS CON > LS B = HS CON = HS B at 5 and 6 wk and LS CON > LS B > HS CON = HS B from 7 to 11 wk. By 8 wk, and thereafter, CFP differed as follows: LS CON > LS B > HS CON > HS B. Group differences in the proportion of individuals that produced CG foam generally supported CFP findings from 4 to 8 wk of age. Body weight did not differ by treatment at 6 wk of age. By 15 wk, TWT were similarly depressed in both HS groups. However, similarly higher 15-wk BW in the LS-CON and HS-B groups contributed to TWT relative to BW differences as follows: LS-B > LS-CON > HS-B; LS-CON = HS-CON; LS-B > HS-CON; and, HS-CON = HS-B. Both selection for exaggerated HPA responsiveness and maternal B treatment negatively affected the reproductive function of HS male offspring.

Long-term effects of intrauterine exposure to mono- n-butyl phthalate on the reproductive function of postnatal rats

Purpose Although it is well known that phthalate esters induce testicular dysfunction in both adult and immature rats, there have been few reports on the long-term effect of phthalate esters on the testicular function of male rats exposed to phthalate esters in utero. This study was designed to assess the long-term effects of the mono- n-butyl phthalate (MBP) ester on the testicular function of neonatal and adult rat offspring from pregnant dams exposed to phthalate esters during gestation. Methods Pregnant rats were administered MBP [0.5 g/(kg body weight/·d); 4 days] by gavage from the 15th to the 18th gestational day. Rats administered solvent only were used as control subjects. After the rats' puberty, using male pups whose testes descended normally, the authors examined their fertility while also measuring their testicular weights, mean seminiferous tubular diameter, and the developmental grade of the germ cells (Johnsen score) in their testes. Next, in neonatal rats, the authors measured the testicular concentration of the Mullerian inhibiting substance (MIS) protein using enzyme-linked immunoassay and the expression level of the MIS messenger RNA using the quantitative polymerase chain reaction method as a marker of the Sertoli cells' function. Next the concentration of testosterone protein using a radioimmunoassay as a marker of the Leydig cells' function was measured. Results The pregnancy rate of the female rats coupled with MBP-treated male rats decreased significantly in comparison with that of the female rats coupled with control male rats ( P < .01). Both the testicular weight and the Johnsen score in the MBP-treated group were decreased significantly more than those of the control group ( P < .05). Neither the concentration of the MIS protein nor the expression level of the MIS messenger RNA in the MBP-treated neonatal testes differed from those of the control testes, whereas the concentration of testosterone protein in the neonate testes decreased significantly in the MBP-treated group in comparison with that of the control group ( P < .01). Conclusions A prenatal short-time exposure to MBP induces a long-term effect on postnatal rats and impairs reproductive function in male offspring probably by inhibiting the Leydig cells' rather than Sertoli cells' function in the fetal period.

Effects of prenatal exposure to 5-fluoro-2'-deoxyuridine on developing central nervous system and reproductive function in male offspring of mice.

The effect of 5-fluoro-2'-deoxyuridine (FrdU) on the developing brain and postpubertal reproductive function of male mouse offspring treated prenatally was investigated. FrdU was administered intraperitoneally to pregnant ICR mice at 1.5, 3, 6, 12.5, 25, and 50 mg/kg/day on days 8 through 13 of gestation or 12.5, 25, and 50 mg/kg/day on days 14 through 18 of gestation. Dams were allowed to deliver spontaneously. Dams treated with FrdU at 12.5, 25, and 50 mg/kg/day on days 8 through 13 of gestation did not deliver because of entire intrauterine death of embryos. Male offspring were aged for 10 or 15 weeks and then cohabited with untreated female mice for assessment of reproductive performance. Histological examination of the testis, epididymis, prostate, and seminal vesicle of offspring at 12 weeks of age, and sperm analysis of offspring at 12 or 17 weeks of age were performed. Dose-dependent decreases in body weight gain were noticed throughout the life of offspring. A marked decrease in the copulation rate was noted in the group treated with FrdU at 6 mg/kg/day on days 8 through 13 of gestation. However, neither histological examination of testes and sex-accessory glands nor sperm analysis revealed adverse effects of FrdU on the reproductive function in the male offspring of dams treated with FrdU at 6 mg/kg/day on days 8 through 13 of gestation. There were no significant differences in the relative weight of testes and epididymides between the group treated with FrdU at 6 mg/kg/day on days 8 through 13 of gestation and the control group. Absolute brain weight in the groups treated with FrdU on days 8 through 13 of gestation significantly decreased, while relative brain weight increased in the group treated at 6 mg/kg/day on days 8 through 13, and at 25 and 50 mg/kg/day on days 14 through 18 of gestation. Dilatation of the lateral and third ventricles was observed in all of the male offspring of dams treated with FrdU at 6 mg/kg/day on days 8 through 13 of gestation, when inspected at 12 and 17 weeks of age. In the subsequent study, ICR mice were treated intraperitoneally with FrdU at 6.25-100 mg/kg on day 12 of gestation, and the fetuses obtained 24 h after treatment. Histological observation was performed in the ventricular zone of telencephalon, and in the ependymal and mantle layers of diencephalon in the fetal brain. The incidence of pyknotic cells in these areas was increased linearly with increasing FrdU dose. From these results and our previous findings, we suggest that damage to the central nervous system, a substantial neuronal deficit, resulting from excessive cell death in the developing brain may lead to reproductive dysfunction after puberty.