The effect of preconceptional exposure of F0 male mice to di(2-ethylhexyl)phthalate on the induction of reproductive toxicity in F2 generation.

The aim of the study was the estimation of the effects of 8 weeks exposure mature and pubescent male mice to DEHP on the prenatal development of the offspring F2 generation. The F1 offspring, of males exposed for whole cycle of spermatogenesis to DEHP (2000 mg/kg bw or 8000 mg/kg bw) and unexposed females, at 8-9 weeks of age were caged males with females from the same group, but from different litter. Eight weeks preconceptional exposure of mature F0 males to 2000 mg/kg bw DEHP induced the significantly higher number of dead fetuses in the F2 offspring; however, the effect on the sperm count and quality of F1 males was not seen. Contrary, after such exposure of pubescent males not significantly decrease in the number of live implants was noted. Results showed that the subchronical, preconceptional exposure of F0 males to DEHP did not influence strongly on the F2 generation of the offspring. Our study did not confirm higher sensitivity germ cells of pubescent males to harmful effects induced by DEHP. The developmental effect was present as the enhanced number of dead implants of F2 generation after exposure of mature F0 males and slight reduction in the number of live fetuses following the exposure of immature males. It may confirm ability to male mediated developmental toxicity.

Reproductive and developmental F1 toxicity following exposure of pubescent F0 male mice to bisphenol A alone and in a combination with X-rays irradiation.

Exposure to environmental toxicants may affect reproduction and development of subsequent generations. This study was aimed at determining the male-mediated F1 effects induced following 8-weeks of subchronic exposure of F0 male mice to bisphenol A (BPA) alone and in a combination with X-rays irradiation (IR) started during their puberty. 4.5 weeks old F0 male mice were exposed to BPA dissolved in ethyl alcohol and diluted in drinking water at the following doses: 5 mg/kg bw, 10 mg/kg bw, 20 mg/kg bw or irradiated with X-rays (0.05 Gy) or exposed to a combination of low doses of both agents (0.05 Gy + 5 mg/kg bw BPA). Immediately after the end of the 8 weeks exposure F0 males were caged with two unexposed females each. Three quarters of the mated females from each group were sacrificed 1 day before expected parturition for examination of prenatal development of the offspring. The remainder of the females from each group were allowed to deliver and rear litters. Pups of exposed males were monitored for postnatal development for 8 weeks. At 8-9 weeks of age 6-8 males from each group of F1 generation were sacrificed to determine sperm count and quality. The current results, compared to the earlier results, showed that exposure of pubescent males to BPA alone or in combination with irradiation may be more damaging to their offspring than the exposure of adult males. The exposure of pubescent males to BPA alone and in combination with irradiation significantly increased the frequency of abnormal skeletons of surviving fetuses, increased the percent of mortality of pups in the F1 generation, reduced the sperm motility of F1 males and may induce obesity. Additionally, the combined BPA and irradiation exposure reduced the number of total and live implantations, whereas the exposure to BPA alone disturbed the male:female sex ratio. The above results may be caused by genetic or by epigenetic mechanisms. Limitation of use of products including BPA, especially by children and teenagers, is strongly recommended.

Three generation study of reproductive and developmental toxicity following exposure of pubescent F0 male mice to di-n-butyl phthalate.

Humans are exposed to phthalates continuously throughout life. The aim of this study was to evaluate the genotoxic effects induced in male mice following 8 weeks of subchronic exposure to di-n-butyl phthalate (DBP) during their puberty and to investigate the possibility of transmission of mutations to subsequent generations via the sperm. Pzh:Sfis outbred male mice aged 4.5 weeks were exposed to DBP by gavage for 8 weeks, 3 days per week to doses of 1/16 LD50 or 1/4 LD50 each time. Six to seven males from each dosage group were sacrificed at 4, 8 and 12 weeks after the start of exposure for examination of sperm count and quality. Immediately after the end of exposure, the remaining males were caged for 1 week with two unexposed females each. Group of females were sacrificed 1 day before expected parturition, whilst other females were allowed to deliver and rear litters. F1 generation males at 8-9 weeks of age were caged with females from the same group, but from a different litter, for examination of prenatal development of the F2 generation. The remaining F1 generation males were sacrificed at the same age to check the sperm count and quality. Our results confirmed the toxic effects of DBP on the reproductive organs and germ cells of pubertally exposed males. The changes induced in male gametes might be transmitted to the next generation via the sperm. The most important effects were induced in the F1 generation. Exposure of F0 males to DBP induced skeletal malformations in surviving foetuses, caused significant mortality in postnatal life and a disturbance in the sex ratio (superior survival of females in F1), as well as increased frequency of DNA damage in the germ cells of F1 males. The present study did not confirm higher sensitivity to DBP of pubescent males compared to adult males, but the effects induced in the F1 generation differed from that after exposure of adult F0 males.

Male-mediated F1 effects in mice exposed to bisphenol A, either alone or in combination with X-irradiation.

We investigated the possible transmission of heritable changes via the sperm, following preconceptional exposure of mice to bisphenol A (BPA), either alone or in combination with X-irradiation. Males were exposed for 8 weeks to BPA, X-rays or both agents, and mated to unexposed females. Pre- and postnatal development of the offspring of exposed males was examined. Both BPA alone and the combined exposure slightly affected postnatal development. Combined exposure induced two-fold higher postnatal mortality than BPA the alone, whereas BPA exposure caused reduced body weight and diminished sperm quality in F1 generation.

Comparison of the effects of bisphenol A alone and in a combination with X-irradiation on sperm count and quality in male adult and pubescent mice.

Bisphenol A (BPA) is employed in the manufacturing of epoxy, polyester-styrene, and polycarbonate resins, which are used for the production of baby and water bottles and reusable containers, food and beverage packing, dental fillings and sealants. The study was designed to examine the effects of 8-week exposure (a full cycle of spermatogenesis) to BPA alone and in a combination with X-irradiation on the reproductive organs and germ cells of adult and pubescent male mice. Pzh:Sfis male mice were exposed to BPA (5, 10, and 20 mg/kg) or X-rays (0.05 Gy) or to a combination of both (0.05 Gy + 5 mg/kg bw BPA). The following parameters were examined: sperm count, sperm motility, sperm morphology, and DNA damage in male gametes. Both BPA and X-rays alone diminished sperm quality. BPA exposure significantly reduced sperm count in pubescent males compared to adult mice, with degenerative changes detected in seminiferous epithelium. This may suggest a higher susceptibility of germ cells of younger males to BPA action. Combined BPA with X-ray treatment enhanced the harmful effect induced by BPA alone in male germ cells of adult males, whereas low-dose irradiation showed sometimes protective or additive effects in pubescent mice.

Two generation reproductive and developmental toxicity following subchronic exposure of pubescent male mice to di(2-ethylhexyl)phthalate.

Di-(2-ethylhexyl)phthalate (DEHP) is widely present in the human environment. The study aimed at the investigation of potential genotoxic effects induced by subchronic exposure to DEHP in germ cells of male mice in the first period of puberty, and to check if the transmission of mutation to the next generation via the sperm is possible. 8-weeks exposure to 2,000 mg/kg and 8,000 mg/kg of DEHP diminished sperm count and quality, leading to a reduced percentage of pregnant females mated to exposed males. A slight increase in the frequency of prenatal deaths and dominant lethal mutations, as well as a significantly increased percentage of abnormal skeletons among the F1 offspring of males exposed to 8,000 mg/kg of DEHP, were observed. Exposure of the fathers did not cause a delay in the postnatal development of the offspring, except for fur development in the group of 8,000 mg/kg of DEHP. Gametes of male offspring of exposed fathers showed reduced motility. The results may suggest that diminished spermaozoa quality induced by DEHP may be coincidental with mutations leading to intrauterine deaths and skeletal abnormalities in the offspring.

Developmental toxicity in mice following paternal exposure to Di-N-butyl-phthalate (DBP).

OBJECTIVE: The aim of the present study was to investigate the effects of paternal Di-N-butyl-phthalate (DBP) exposure pre- and postnatally on F1 generation offspring, and prenatally on F2 generation offspring. METHODS: Male mice were exposed to either 500 mg/kg or 2 000 mg/kg of DBP for 8 weeks, and mated with non-exposed females. Three-quarters of the females were sacrificed a day prior to parturition, and examined for the number of living and dead implantations, and incidence of gross malformations. Pups from the remaining females were assessed for developmental markers, growth parameters, as well as sperm quantity and quality. RESULTS: There were no changes in the fertility of parents and in intrauterine development of the offspring. Pups of DBP-exposed males demonstrated growth-retardation. Following paternal exposure to 500 mg/kg bw of DBP, there were almost twice the number of males than females born in the F1 generation. F1 generation females had a 2.5-day delay in vaginal opening. Paternal exposure to 2 000 mg/kg bw of DBP increased the incidence of sperm head malformations in F1 generation males; however, there were no changes in the fertility and viability of foetuses in the F2 generation. CONCLUSION: Paternal DBP exposure may disturb the sex ratio of the offspring, delay female sexual maturation, and deteriorate the sperm quality of F1 generation males.

[The effects of di-n-butyl phthalate on the somatic cells of laboratory mice]. / Wplyw ftalanu di-n-butylu (DBP) na komórki somatyczne myszy laboratoryjnych.

Phthalates are widely used as a plasticizers in manufacture of synthetic materials and as solvents in sanitary products, cosmetics and pharmaceutical products. Dibutylphthalate (DBP) is used as a plasticizers and as a textile lubricating agent and as solvent in printing ink. The study aimed the evaluation of the magnitude of DNA damage in liver and bone marrow cells and estimation of dibutyl phthalate (DBP) concentration in peripheral blood following prolonged exposure to DBP. Experiments were conducted an the Pzh:Sfis male mice. Animals were exposed 8 weeks, 3 days per week per os to DBP suspension in oil in doses of 500 mg/kg bw (1/16 LD50) and 2000 mg/kg bw (1/4 LD50). Following groups of mice were sacrificed 4 and 8 weeks after the start of exposure and 4 weeks after the end of exposure. Decreased body weight of mice and statistically significant decreased liver and relative liver weights were observed following 8-weeks exposure to 2000 mg/kg bw DBP. In the same time higher however not statistically significant level of DNA damage measured by Comet assay in liver cells were noted. DBP did not induce enhanced frequency of DNA damage in bone marrow cells. Following 8-weeks exposure to the dose of 2000 mg/kg bw DBP the increased level of DBP in peripheral blood was observed. Enhanced levels of DBP were still noted 4 weeks after the termination of exposure. Results confirmed that DBP acts as a weak mutagen for DNA of somatic cells. However, following prolonged exposure this compound seems to undergo slower metabolism and was reaching temporarily higher levels in peripheral blood.

Is concentration and motility of male gametes related to DNA damage measured by comet assay?

Approximately 8 percent of couples in the World have problem with offspring production. Male infertility, which is the reason of the half of reproduction failures, is connected with diminished sperm production and deterioration of its quality. One important factor which affects fertility is the appearance of DNA damage in germ cells leading to enhanced frequency of mutations. This study aimed to compare the frequency of DNA damage in human spermatozoa in samples of different sperm concentration and motility. The anonymous sperm sample donors were men aged from 20-44 years, couples of pregnant females. Sperm concentration, motility and DNA damage measured by Comet assay were estimated. The following parameters were chosen for analysis of DNA damage: percent of DNA in comet head, comet tail length, tail moment. There were no differences in the mean DNA damage in male gametes between different age groups of donors, nor between samples of different sperm motility. The correlation between low sperm concentration in ejaculate and enhanced level of DNA damage was observed. The highest DNA damage was noted in samples with low sperm concentration. In gametes from this group, the lowest percent of DNA in comet head, the highest mean tail length, and the highest tail moment were observed.

The effects of di-n-butyl phthalate on the germ cells of laboratory mice.

Phthalate are found in the environmental samples due to their wide use in the industry as plasticizers. Di-n-butylphthalate (DBP) is mainly used in nitrocellulose and polyvinyl acetate products as well as in personal-care products. This study was performed to investigate the influence of exposure to DBP on the quantity and quality (motility, morphology) and DNA damage (induction of micronuclei and DNA strand breaks) of male mice gametes. The estimation of DBP residues was also done. Eight weeks exposure to DBP (500 mg/kg bw and 2000 mg/kg bw) did not significantly affect testes and epididymes weights as well as sperm count. DBP clearly diminished sperm motility, enhanced frequency of abnormal sperm heads and not significantly increased DNA strand breaks in germ cells as well as frequency of micronuclei in spermatids. There were no bioacumulation of DBP in mice. Results suggest that DBP may affect the male mice germ cells.

[Effects of subchronic exposure of laboratory mice to benzylbutyl phthalate (BBP) on the quantity and quality of male germ cells]. / Badanie wplywu ftalanu butylobenzylu (BBP) na ilosc i jakosc gamet meskich przy subchronicznym narazeniu myszy laboratoryjnych.

The aim of the study was to investigate the effect of 8-weeks exposure of male mice to benzyl butyl phthalate (BBP) on the sperm count and quality of gametes. Pzh:Sfis male mice exposed per os to 450 mg/kg bw (1/16 LD50) and to 1800 mg/kg bw (1/4 LD50) of BBP in olive oil were used in the study. Control mice were treated with olive oil only. Groups of animals were killed 4 and 8 weeks after the start of exposure and 4 weeks after he end of exposure. Sperm count, motility, morphology and DNA damage in gametes were estimated in the study. Sperm counts were diminished 4 and 8 weeks after the start of exposure to BBP. In the same time decrease in sperm motility and dose-dependent increase in the frequency of abnormal sperm heads and slight increase in DNA damage were noted. 4 weeks after the end of exposure, slight decrease in sperm counts in the group of 1/4 LD50 was observed, only. Correlation between sperm count and testes and epididymes weight were noted. Themost sensitive to BBP exposure occurred spermatozoa and spermatids.

Semen quality in relation to xenohormone and dioxin-like serum activity among Inuits and three European populations.

BACKGROUND: Semen quality in humans may be influenced by exposure to endocrine-disrupting compounds. OBJECTIVES: We analyzed associations between semen characteristics and serum xenoestrogen receptor (XER), xenoandrogen receptor (XAR), and aryl hydrocarbon receptor (AhR) transactivity. XER and XAR activity were measured in serum samples cleared for endogenous steroid hormones and AhR activity in raw lipophilic serum extracts free of proteins. RESULTS: All together, 319 men from Warsaw (Poland), Greenland, Kharkiv (Ukraine), and Sweden provided semen and blood samples. No strong and consistent associations between xenobiotic activity and semen quality measures were observed in the four populations. However, when the data were combined across populations sperm concentration increased 40% per unit increase in XER activity [95% confidence interval (CI), 1-79%] in the subgroup with XER activity below the reference level. Among subjects with XER activity above the reference level an increase of 14% (95% CI, 2-28%) was found. Furthermore, an increase of 10% motile sperm per unit increase in XER activity below reference level (95% CI, 0.2-20) was found. We are unable to exclude that the associations are chance findings. CONCLUSION: Alteration of XER, XAR, or AhR transactivity within the range found in serum from the general European and Inuit population seems not to markedly deteriorate sperm cell concentration, motility, or morphology in adult men.

Semen quality and exposure to persistent organochlorine pollutants.

BACKGROUND: Inconsistent results have been found in previous human studies on male reproductive toxicity of persistent organochlorine pollutants. The majority of studies have been conducted among selected populations of infertility clients or among occupational cohorts including a limited number of participants. METHODS: We conducted a cross-sectional study of semen quality and serum concentration of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) among 763 men. We included men from all regions in Greenland (n = 194), fishermen from Sweden (n = 185), inhabitants of the city of Kharkiv, Ukraine (n = 195), and inhabitants of the city of Warsaw, Poland (n = 189). Blood samples were analyzed for CB-153 and p,p'-DDE using gas chromatography-mass spectrometry and adjusted for serum lipids. RESULTS: Sperm concentration was not impaired with increasing serum CB-153 or p,p'-DDE levels in any of the separate groups or overall. Similarly, the proportion of morphologically normal sperm was not associated with either CB-153 or p,p'-DDE blood concentration. However, sperm motility was inversely related to CB-153 concentration in Greenland and the Swedish fishermen population. Across all 4 regions, the sperm motility decreased on average by 3.6% (95% confidence interval = 1.7% to 5.6%) per one-unit increase in the log of blood CB-153 (ng/g lipid). The concentration of p,p'-DDE was negatively associated with sperm motility in the Greenlandic population and in the compiled dataset. CONCLUSION: Adult exposure to persistent organochlorine pollutants within the ranges observed in the present study is not likely to cause reduction in sperm concentration or morphology. However, higher exposure may be associated with impaired sperm motility.

Quality control workshops in standardization of sperm concentration and motility assessment in multicentre studies.

Semen quality has been reported to vary markedly between different regions. To properly assess the differences among countries a minimization of the variation among centres in the assessments of sperm quality is essential. We here report on the training and two subsequent follow-up workshops on assessments of sperm concentration and motility. A total of 26 fresh ejaculates were analysed by four persons who were collecting these data in a multicentre study on sperm quality. In addition, two trained technicians from one of the laboratories analysed the samples. At the first training workshop, the median coefficient of variation among centres in sperm concentration was 27.7%, but decreased markedly to 17.0% at the second workshop and 8.1% (p = 0.048) at the third workshop. The CV for evaluation of the proportion of progressive motile sperm decreased less and not statistically significant from 16.5 to 14.1% and 11.0% (p = 0.94). At the third workshop there were no statistical significant differences among centres in assessments of sperm concentration or motility (p > 0.57). Furthermore the coefficient of variation in assessments of sperm concentration and motility among centres were at the same level as between two trained technicians (p > 0.72). This study indicates that training and subsequent follow-up workshops can assure minimum variability among centres in assessments of sperm concentration and motility.