OBJECTIVE: To investigate the effects of diethylhexyl phthalate (DEHP) exposure on anxiety-like behaviors and learning and memory ability in mice and explore the underlying mechanism. METHODS: Forty male ICR mice were randomized equally into control group (0 mg/kg) and 10, 50 and 100 mg/kg DEHP exposure groups, in which the mice were exposed to DEHP at the indicated doses by gavage for 4 weeks. After the treatments, the mice were assessed for behavioral changes using open filed test, elevated plus-maze and Morris water maze test. Brain tissues were collected from the mice for determination of malondialdehyde (MDA) content, pathologies and expressions of ZO-1 and occludin in the hippocampus. RESULTS: Compared with the control group, the mice with DEHP exposure for 4 weeks exhibited no significant body weight change (P>0.05) but presented with obvious behavioral changes, manifested by reduced movement distance (P < 0.05) and time spent in the center of the open field (P < 0.05), reduced movement distance (P < 0.05) and time spent in the open arm of the elevated maze (P < 0.05), significantly increased latency of searching for the platform (P < 0.05), and decreased frequency of crossing the platform (P < 0.05). HE staining showed obvious vertebral cell death in the hippocampal CA1 to CA3 regions of the mice with DEHP exposure. The exposed mice showed significantly increased MDA content and decreased expressions of ZO-1 and occludin at both the mRNA and protein levels in the hippocampus (P < 0.05 or 0.01). Multivariate linear regression analysis suggested a close correlation between anxiety-like behaviors and learning and memory abilities in DEHP-exposed mice. CONCLUSION DEHP exposure may cause damages of the blood-brain barrier and the pyramidal cells in the hippocampus of mice, thereby inducing anxiety-like behaviors and learning and memory impairment.
Animals ; Anxiety/chemically induced* ; Blood-Brain Barrier/metabolism* ; Diethylhexyl Phthalate/toxicity* ; Male ; Maze Learning ; Mice ; Mice, Inbred ICR ; Occludin/pharmacology*

OBJECTIVETo investigate the effect of the exposure to di- (2-ethylhexyl) phthalate (DEHP) during pregnancy on the DNA methylation level of genomes in the testis of the offspring in mice.

METHODSPregnant KM mice were randomly divided into three groups, normal control, corn oil and DEHP-exposed. Corn oil and DEHP (500 mg/[kg x d]) were administrated respectively from gestation day 12.5 (GD 12.5) to postnatal day 3 (PND 3). The testes of the offspring were excised on PND 7, and their genomic DNA was treated with EcoR I /Msp I and EcoR I /Hpa II. The genome-wide DNA methylation patterns of the CCGG sites were detected by methylation-sensitive amplification polymorphism (MSAP). The samples were electrophoresed in the ABI 3730 DNA sequencer and the results analyzed by the Genescan3.1.

RESULTSThe average incidence of DNA methylation was (34.03 +/- 3.05)% in the DEHP-exposed mice, obviously higher than (28.37 +/- 2.37)% in the normal control and (28.58 2.45)% in the corn oil group, with statistically significant differences (P < 0.05).

CONCLUSIONExposure to DEHP during pregnancy increases the DNA methylation level of the genome in the testis of the offspring and affects the apparent genetic modification of the genome, which may be one of the important toxicological causes of the lesion in the reproductive system.

Animals ; DNA Methylation ; drug effects ; Diethylhexyl Phthalate ; pharmacology ; Female ; Genome ; Male ; Mice ; Mice, Inbred Strains ; Pregnancy ; Prenatal Exposure Delayed Effects ; Random Amplified Polymorphic DNA Technique ; Testis ; drug effects

OBJECTIVETo observe the effects of diethlhexyl phthalate (DEHP) on lipid peroxidation and the life span in Drosophila melanogaster.

METHODSFed Drosophila with the concentration 0.20% DEHP of exposure after 0, 14, 28 days, the activity of total superoxide dismutase (SOD), CuZn-SOD and the concentration of malondialdehyde were determined. At the same time, the longevity test was carried out to examine the effect of DEHP on the Drosophila's lifespan.

RESULTSThe lifespan of Drosophila was shortened in a dose of DEHP exposed groups. The indexes of mean life span (MLS), 50% lethal time and mean maximum life span in three DEHP-treated groups (concentration of 0.05%, 0.10% and 0.20%) were lower than those of the controlled group respectively (P < 0.01 or P < 0.05). The MLS of both Drosophila sexes were reduced from the control of 64 days and 59 days to the test 60 days-52 days and 54 days-49 days respectively. DEHP decreased the activity of SOD (P < 0.01 or P < 0.05), and lead to a time-dependent relation and an increase in the concentration of malondialdehyde (P < 0.01 or P < 0.05) in the DEHP-exposed Drosophila groups.

CONCLUSIONDEHP might promote the process of lipid peroxidation and shorten the life span in Drosophila melanogaster. It should be one of the reasons in the senescence of Drosophila.

Animals ; Diethylhexyl Phthalate ; pharmacology ; Drosophila melanogaster ; drug effects ; growth & development ; metabolism ; Female ; Lipid Peroxidation ; drug effects ; Longevity ; drug effects ; Male ; Malondialdehyde ; metabolism ; Superoxide Dismutase ; metabolism ; Time Factors

OBJECTIVETo explore the effects of Di (2-ethylhexyl) phthalate (DEHP) on the testis and testicular gubernaculum of fetal KM mice in vivo and to investigate the mechanism of DEHP-induced cryptorchidism.

METHODSThirty healthy pregnant KM mice were randomly and equally divided into a blank control group, a corn oil control group and a DEHP group. The pregnant mice in the latter group were exposed to DEHP by gavage at the dose of 500 mg/kg body weight per day from gestation day 12 (GD12) through gestation day 19 (GD19). The effects of DEHP were observed on the number of fetuses per pregnancy, the ratio of male to female pups, the weight of the testis, the morphology and location of the testis and gubernaculum, the relative testis-bladder neck distance (TBD) and cranial suspensory ligament (CSL) residual. The expressions of the androgen receptor (AR), estrogen receptor (ER) and actin and proliferating cell nuclear antigen (PCNA) in the gubernaculum were detected by immunohistochemistry.

RESULTSDEHP reduced the testis weight and TBD, induced different degrees of testis maldescent, but produced no obvious effect on the body weight, the number of fetuses per pregnancy, the sex ratio and the testis gubernacular morphology. Under the light microscope, hypotrophy was seen in all the testis seminiferous tubules, spermatogenic cells and Sertoli cells, marked Leydig cell hyperplasia was noted, and the positive expression of AR in the gubernaculum was decreased in the DEHP group (P < 0.01).

CONCLUSIONDEHP could cause dysfunction of the testis gubernaculum via its anti-androgen effect, induce cryptorchidism, and cause dysplasia and dysfunction of Sertoli cells, Leydig cells and spermatogenic cells in fetal mice.

Animals ; Diethylhexyl Phthalate ; pharmacology ; Female ; Fetus ; drug effects ; Leydig Cells ; drug effects ; Male ; Mice ; Mice, Inbred Strains ; Pregnancy ; Sertoli Cells ; drug effects ; Testis ; cytology ; drug effects ; pathology

OBJECTIVE: Prenatal phthalate exposure has been associated with placental inflammatory factors and infant allergic rhinitis (AR). However, the results are inconclusive. We designed a population-based cohort study to examine the effects of placental inflammatory biomarkers on the sex-dependent associations between maternal phthalate exposure and infant AR. METHODS: A total of 2,348 pregnant women from Ma'anshan, Anhui Province, China, who were screened before antenatal visits and met the inclusion criteria, were included in the present study. We assessed AR in their offspring aged 36 months with a questionnaire. Quantitative PCR was performed to measure placental inflammatory factor mRNAs. The independent samples t-test and multivariable logistic regression were used to determine the associations between infant AR and maternal phthalates. RESULTS: Childhood AR may be related to education and family monthly income ( P = 0.01). The phthalate metabolites, mono (2-ethylhexyl) phthalate (MEHP), mono (2-ethyl-5-hydroxyl) phthalate (MEHHP), in pregnant women were associated with a significantly increased risk for infant AR in males [ P < 0.05; odds ratio ( OR): 1.285; 95% confidence interval ( CI): 1.037-1.591, and OR: 1.232, 95% CI: 1.008-1.507, respectively], but not females. Additionally, irritably-increased expression levels of HO-1 and IL-4 were associated with AR in male infants ( OR: 1.175; 95% CI: 1.038-1.329 and OR: 1.181; 95% CI: 1.056-1.322, respectively). The association between maternal urinary MEHHP and placental HO-1 was marginally significant according to mediation analysis. CONCLUSION The associations of maternal MEHHP and MEOHP levels with fetal AR in males were significant. Placental HO-1 was a fractional mediator in the associations between MEHHP and AR. Thus, the placenta should be further investigated as a potential mediator of maternal exposure-induced disease risk in children.
Biomarkers ; Child, Preschool ; Cohort Studies ; Diethylhexyl Phthalate/analogs & derivatives* ; Female ; Humans ; Interleukin-4/pharmacology* ; Male ; Maternal Exposure/adverse effects* ; Phthalic Acids/adverse effects* ; Placenta ; Pregnancy ; Rhinitis, Allergic/epidemiology*

OBJECTIVETo investigate the effects of mono(2-ethylhexyl) phthalate(MEHP), the primary metabolite of di(2-ethylhexyl) phthalate (DEHP), on testosterone biosynthesis in Leydig cells cultured from the Sprague Dawley rat testis.

METHODSBased on the primary Leydig cell culture model, MEHP exposure groups involved control (0 micromol/L), 62.5, 125, 250, 500 and 1000 micromol/L. We observed mitochondria activity with the MTT method, measured the testosterone level with RIA and determined steroidogenesis acute regulatory protein (StAR) mRNA expression with RT-PCR.

RESULTSAfter Leydig cells were exposed to MEHP for 24 hours, the activity of mitochondria enhanced evidently at 250 micromol/L and then declined markedly at 1000 micromol/L compared with the control group (P < 0.01). The testosterone level showed an increasing tendency in both basal and hCG-stimulated states with statistical significance at 250 and 500 micromol/L compared with the control group (P < 0.01). However, the expression of StAR mRNA appeared unchanged at 62.5, 125 or 250 micromol/L, but exhibited a decreasing tendency at 500 and 1000 micromol/L (P < 0.01).

CONCLUSIONME- HP directly affected the activity of mitochondria and testosterone biosynthesis of the Leydig cells in vitro. StAR, the regulator of cholesterol transport into mitochondria, might not be responsible for the increase of testosterone biosynthesis induced by MEHP.

Animals ; Cells, Cultured ; Diethylhexyl Phthalate ; analogs & derivatives ; pharmacology ; Dose-Response Relationship, Drug ; Leydig Cells ; drug effects ; metabolism ; Male ; Phosphoproteins ; biosynthesis ; genetics ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Testosterone ; biosynthesis

OBJECTIVETo explore the effects of di(2-ethylhexyl)phthalate (DEHP) on neonatal mice's testes and Leydig cells in vivo.

METHODSPregnant mice were exposed to DEHP at the dose of 100 mg/kg, 200 mg/kg or 500 mg/kg (body weight) per day by gavage from gestation day 12 (GD 12) through postnatal day 3 (PND 3), respectively. The testis and body weights, testicular histopathology and the activity of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) of the neonatal mice were investigated.

RESULTSThe body and testis weights of the male mice's offspring were significantly reduced following DEHP exposure. Leydig cell morphology was affected significantly by DEHP as compared with the controls. Leydig cells obviously increased in the neonatal mice's testes on PND 15 and PND 30 when exposed to DEHP (500 mg/[kg x d]). Activities and positive area of the steroidogenic enzymes 3beta-HSD immunoexpression decreased markedly when exposed to DEHP (100 mg/[kg x d] or 200 mg/[kg x d]). Image analysis showed a decrease in the activities of 3beta-HSD in the animals exposed to DEHP (500 mg/[kg x d]), but an increase in the positive area of 3beta-HSD immunoexpression as compared with the control animals on PND 15 (P < 0.01).

CONCLUSIONDEHP affects the Leydig cell morphology, the activity of 3beta-HSD, the testis and body weights and the testicular histopathology of neonatal mice, and it may function as an antiandrogenic agent.

3-Hydroxysteroid Dehydrogenases ; metabolism ; Animals ; Animals, Newborn ; Diethylhexyl Phthalate ; pharmacology ; Dose-Response Relationship, Drug ; Female ; Leydig Cells ; cytology ; drug effects ; Male ; Mice ; Mice, Inbred Strains ; Pregnancy ; Prenatal Exposure Delayed Effects ; Testis ; drug effects

Phospholipid hydroperoxide glutathione peroxidase(PHGPx), an antioxidative selenoprotein, is modulated byestrogen in the testis and oviduct. To examine whetherpotential endocrine disrupting chemicals (EDCs) affectthe microenvironment of the testes, the expression patternsof PHGPx mRNA and histological changes were analyzedin 5-week-old Sprague-Dawley male rats exposed to severalEDCs such as an androgenic compound [testosterone (50,200, and 1,000microg/kg)], anti-androgenic compounds [flutamide(1, 5, and 25mg/kg), ketoconazole (0.2 and 1mg/kg), anddiethylhexyl phthalate (10, 50, and 250mg/kg)], andestrogenic compounds [nonylphenol (10, 50, 100, and 250mg/kg), octylphenol (10, 50, and 250mg/kg), and diethyl-stilbestrol (10, 20, and 40microg/kg)] daily for 3 weeks via oraladministration. Mild proliferation of germ cells andhyperplasia of interstitial cells were observed in the testesof the flutamide-treated group and deletion of thegerminal epithelium and sloughing of germ cells wereobserved in testes of the diethylstilbestrol-treated group.Treatment with testosterone was shown to slightly decreasePHGPx mRNA levels in testes by the reverse transcription-polymerase chain reaction. However, anti-androgeniccompounds (flutamide, ketoconazole, and diethylhexylphthalate) and estrogenic compounds (nonylphenol,octylphenol, and diethylstilbestrol) significantly up-regulated PHGPx mRNA in the testes (p<0.05). Thesefindings indicate that the EDCs might have a detrimentaleffect on spermatogenesis via abnormal enhancement ofPHGPx expression in testes and that PHGPx is useful as abiomarker for toxicity screening of estrogenic or anti-androgenic EDCs in testes.
Androgen Antagonists/pharmacology ; Animals ; Diethylhexyl Phthalate/pharmacology ; Diethylstilbestrol/pharmacology ; Endocrine Disruptors/*pharmacology ; Estrogens, Non-Steroidal/pharmacology ; Flutamide/pharmacology ; Glutathione Peroxidase/*biosynthesis/genetics ; Histocytochemistry ; Ketoconazole/pharmacology ; Male ; Phenols/pharmacology ; RNA, Messenger/*biosynthesis/genetics ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Spermatogenesis/drug effects ; Testis/*drug effects/*enzymology ; Testosterone/pharmacology

ObjectiveTo explore the antagonistic effect of vitamin E (VE) on male reproductive toxicity induced by di-2-ethylhexyl phthalate (DEHP) in pubertal SD rats and its underlying mechanisms.

METHODSThirty 5-week-old male SD rats were randomly divided into five groups of equal number, corn oil control, low-dose (10 mg/kg/d), medium-dose (100 mg/kg/d) and high-dose DEHP exposure (500 mg/kg/d), and VE intervention (high-dose DEHP + VE ［100 mg/kg/d］), and treated respectively for 30 successive days. At 3 days after treatment, the testes of the animals were harvested for determination of the oxidative stress index, serum reproductive hormone levels, cauda epididymal sperm parameters, and expressions of cell apoptosis-related genes and proteins.

RESULTSCompared with the control group, the rats of the medium- and high-dose DEHP groups showed significant decreases in the levels of such serum reproductive hormones as follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T), sperm parameters as average path velocity (VAP), straight line velocity (VSL), curvilinear velocity (VCL), straightness (STR), linearity (LIN) and wobble (WOB), and the activities of superoxide dismutase (SOD) and glutathione peroxide (GSH-Px), but significant increases were observed in the latter two groups in the content of malondialdehyde (MDA)(［3.32±0.87］ nmol/mg pro vs ［2.13±0.49］ nmol/ mg pro), mRNA expressions of Bad, Bax, Cytochrome C, Caspase-3 and the Bax/Bcl-2 ratio, and protein expressions of Cytochrome C and Caspase-3. In comparison with the high-dose DEHP group, the VE intervention group exhibited remarkably increased serum LH and T levels, sperm VAP, VSL, VCL, STR and WOB, and activities of SOD and GSH-Px, but markedly decreased mRNA expressions of Bad, Bax, Cytochrome C, Caspase-3 and the Bax/Bcl-2 ratio as well as the protein expressions of Cytochrome C and Caspase-3 in the testis tissue (P<0.05).

CONCLUSIONSExposure to DEHP induces androgen secretion disorders, causes oxidative damage to the testicular tissue, activates the mitochondrial apoptosis pathway in the testis, and ultimately reduces the quality of epididymal sperm, while VE can protect the rat testis from DEHP-induced reproductive toxicity.

Animals ; Antioxidants ; pharmacology ; Apoptosis ; genetics ; Autophagy-Related Protein 5 ; metabolism ; Caspase 3 ; metabolism ; Diethylhexyl Phthalate ; antagonists & inhibitors ; Epididymis ; Follicle Stimulating Hormone ; blood ; Luteinizing Hormone ; blood ; Male ; Malondialdehyde ; metabolism ; Mitochondria ; drug effects ; Oxidative Stress ; drug effects ; Oxidoreductases ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reproduction ; Spermatozoa ; drug effects ; physiology ; Superoxide Dismutase ; metabolism ; Testis ; drug effects ; Testosterone ; blood ; Vitamin E ; pharmacology

AIMTo determine the biochemical effect of di-(2-ethylhexyl) phthalate (DEHP) on testes, liver, kidneys and pancreas on day 10 in the process of degeneration of the seminiferous epithelium.

METHODSDiets containing 2% DEHP were given to male Crlj:CD1(ICR) mice for 10 days. The dose of DEHP was 0.90 +/- 0.52 mg/mouse/day. Their testes, livers, kidneys and pancreata were examined for detection of mono-(2-ethylhexyl) phthalate (MEHP), nitrogen oxides (NOx) produced by peroxidation of nitric oxide (NO) with free radicals, and lipid peroxidation induced by the chain reaction of free radicals.

RESULTSHistological observation and serum analysis showed the presence of severe spermatogenic disturbance, Leydig cell dysfunction, liver dysfunction and dehydration. Unexpectedly, the concentration of MEHP in the testes was extremely low compared with that in the liver. However, the concentration of the NOx in the testes was as high as the hepatic concentration. Furthermore, free radical-induced lipid peroxidation was histochemically detected in the testes but not in the liver.

CONCLUSIONThe results indicate that DEHP-induced aspermatogenesis is caused by the high sensitivity of the testicular tissues to MEHP rather than the specific accumulation or uptake of circulating MEHP into the testes.

Animals ; Body Weight ; drug effects ; Copper ; metabolism ; Diethylhexyl Phthalate ; analogs & derivatives ; metabolism ; pharmacology ; Iron ; metabolism ; Kidney ; drug effects ; metabolism ; Lipid Peroxidation ; drug effects ; Liver ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred ICR ; Nitrogen Oxides ; metabolism ; Pancreas ; drug effects ; metabolism ; Spermatogenesis ; drug effects ; Testis ; drug effects ; metabolism ; Testosterone ; blood ; Zinc ; metabolism