The present study was to investigate whether metallothionein(MT)was involved in sensitivity of testis to cadmium (Cd) and protection of rats from Cd-induced testis damages.The rats were treated by intraperitoneal injection with 0.2,0.4,and 0.8mgCd/kg BW for 7days.The atomic absorption spectrophotometry and cadmium hemoglobin affinity assay were applied to evaluate the contents of Cd and MT in testis and liver.The testis glutathione(GSH),malondialdehyde(MDA)and daily sperm production were measured.There were substantial increases of both Cd and MT in the liver after Cd exposure.The testis Cd and MT contents were lower than those in the corresponding liver in Cd-exposed rats.Low doses of Cd (0.2and0.4 mg/kgBW) induced MT in testis,while a significant decline of MT was found in rats treated with 0.8mgCd/kgBW. By a concomitant decrease of MT,there was an obvious increase of MDA and marked decreases of GSH,daily sperm production in rats treated with 0.8mgCd/kgBW.These findings suggested MT was more difficult to be induced in the testis than in the liver by Cd,which might account for the high susceptibility of testis to Cd.MT, increased by a low dose of Cd,played an important role in protecting testis against Cd toxicity by sequestering and antioxidating.

Fenvalerate,a synthetic pyrethroid insecticide,is widely produced and used worldwide.To explore fenvalerate-induced genotoxic effects, particularly numerical chromosome aberration (CA),we firstly examined conventional semen parameters, the progression and motion parameters of the spermatozoa among 12 fenvalerate-exposed workers and 30 donors of the internal and external control groups.Then numerical CA of chromosome X,Y and 18 were investigated by multicolor fluorescence in situ hybridization (FISH).The results showed the significant differences in the percentage of sperm abnormality between fenvalerate-exposed group and the external control group (P=0.024).In aneuploid parameters,the frequency (mean

The effect of terephthalic acid (TPA) on urinary bladder carcinogenesis was examined.Male Wistar rats were initiated by injection of N-Methyl-N-Nitrosourea (MNU)(20mg/kg b.w.ip) twice a week for 4 weeks,then given basal diet containing 5% TPA,5% TPA plus 4% Sodium bicarbonate (NaHCO3) and 1%TPA for the next22weeks, and then euthanized. 5%TPA treatment induced a high incidence of urinary bladder calculi and a large amount of precipitate.Though 5% TPA plus 4% Sodium bicarbonate(NaHCO3)and 1% TPA treatment did not induce urinary bladder calculi formation,they resulted in a moderate increase in urinary precipitate.Histological examination of urinary bladder revealed that MNU-5% TPA treatment resulted in a higher incidence of simple hyperplasia,papillary or nodular hyperplasia (PN hyperplasia), papilloma and cancer than MNU control.MNU-5% TPA plus 4% Sodium bicarbonate (NaHCO3) and 1% TPA treatment increased slightly the incidence of simple hyperplasia and PN hyperplasia(not statistically significant). The major elements of the precipitate are phosphorus, potassium, sulfur, chloride, calcium and TPA. The present study indicated that the calculi induced by TPA had a strong promoting activity on urinary bladder carcinogenesis and the precipitate containing calcium terephthalate (Ca TPA) may also have weak promoting activity on urinary bladder carcinogenesis.

Carbaryl is known to impede female reproductive function,however,the mechanisms through which the adverse effects are mediated are not clearly elucidated.In order to get insight into the mechanisms,this study was conducted to raise fresh concerns about the potential effects of carbaryl on steroidogenesis by primary human granulosa-lutein cells(hGLCs)and explore the possible nature of this action.hGLCs were co-incubated with various concentrations of carbaryl at 0,1,5,25,125μmol/L for 24 h to examine effects of this carbamate pesticide on progesterone accumulation. We observed that the carbaryl inhibited basal and FSH-induced progesterone production in a dose-dependent manner.We also investigated the effects of carbaryl on 22(R)-hydroxycholesterol(22R-HC)-stimulated progesterone yield,basal and FSH-stimulated StAR gene expression and cyclic adenosine monophosphate(cAMP)production,as well as forskolin(non-specific activator of adenylyl cyclase)-induced progesterone and cAMP production of hGLCs.We found that the decreased progesterone biosynthesis was accompanied with a reduced cAMP abundance on both basal and FSH-induced condition.Furthermore, our results demonstrated that the 22R-HC could remove the carbaryl-induced restraint of progesterone biosynthesis,suggesting that carbaryl caused a disruption of cholesterol transport across mitochondrial membranes,which was further confirmed by the observation that carbaryl inhibited the gene expression of steroidogenic acute regulatory protein (StAR).In addition,the inhibitory effects of carbaryl on progesterone and cAMP production were completely reversed by addition of forskolin to the cell culture,which indicated a repaired site on the upstream components of adenylate cyclase or adenylate cyclase per se by carbaryl in the cAMP-mediated signal pathway.All the effects mentioned above were not due to a detrimental action of carbaryl on cell viability by MTS assay.In conclusion,carbaryl may inhibit steroidogenesis,at least in part,by obstructing the delivery of cholesterol over mitochondrial membranes and attenuating cAMP generation.

Purpose:Folate deficiency and reduced DNA repair capacity are established risk factors for squamous cell carcinoma of the head and neck(SCCHN). We hypothesized that polymorphisms of the thymidylate synthase(TYMS)gene,which regulates a key enzyme in folate metabolism required for DNA synthesis and repair, are associated with SCCHN risk. Experimental Design:In a hospital-based case-control study of 704 SCCHN cases and 1,085 controls, frequency matched by age,sex, nd ethnicity,we genotyped the TSER(thymidylate synthase in the 5'-untranslated enhanced region)and TS3ˊUTR(thymidylate synthase in the 3'-untrans-lated region) polymorphisms. Results: The TS3ˊUTR 0bp/0bp genotype was associated with a significantly decreased risk of SCCHN[adjusted odd ratio(OR)=0.67,95%confidence interval (CI)=0.47-0.94] compared with the 6bp/6bp genotype, but the TSER polymorphism had no main effect on risk of SCCHN. When we evaluated the two polymorphisms together by the number of protective alleles(the TSER 3R and TS3'UTR 0bp alleles), we found that the combined genotypes with four protective alleles(the TSER 3R3R and TS3'UTR 0bp/0bp) was associated with significantly decreased SCCHN risk (OR=0.60, 95%CI=0.37-0.98). In addition,the TS3ˊUTR 0bp genotypes were associated in an allele dose-dependent manner with a decreased risk of overall stage IV oral cancer (OR=0.84, 95%CI=0.52-1.34 for the 6bp/0bp genotype and OR=0.26, 95%CI=0.08-0.87 for the 0bp/0bp genotype; Ptrend=0.035). Conclusion: The TSER and TS3'UTR polymorphisms are associated with SCCHN risk. The TSER 3R and TS3ˊUTR 0bp alleles seemed to jointly protect against SCCHN. In particular, the 0bp allele seemed to protect against oral cancer progression.

Fenvalerate,a synthetic pyrethroid,is widely used in agriculture and other domestic applications in China.Recently,Fenvalerate has been suspected to be one of the endocrine-disrupting chemicals(EDC).In this study, we investigated the effects of fenvalerate on follicle-stimulating hormone(FSH)-stimulated progesterone (P4) production by human ovarian luteinizing-granulosa cells (hGLCs). After 24 h incubation,fenvalerate inhibited FSH-stimulated P4 production.At the same time, FSH-stimulated cAMP also decreased.Due to calcium and Ca2+-calmodulin (CaM) system involving gonadotropin-stimulated steroidogenesis by granulosa cells,we then evaluated the effects of fenvalerate on trifluoperazine (TFP)-and verapamil-driven FSH-stimulated P4 production.The results showed that calcium or calmodulin might play a role in fenvalerate-induced alterations in FSH-stimulated P4 biosysthesis.Then,the effects of fenvalerate on calcium homeostasis in hGLCs were studied. The result showed that 5μM fenvalerate induced a slow increase in[Ca2+] in hGLCs by using a fluorescent Ca2+ indicator fluo-3/AM. The changes in total concentration of CaM in hGLCs induced by fenvalerate were evaluated by a method of immunofluorescence. There is a significant increase in all treated groups.In summary, fenvalerate could inhibit FSH-stimulated P4 production. Also, fenvalerate interferes with calcium homeostasis in hGLCs. The effects of fenvalerate on FSH-stimulated ovarian steroidogenesis may be mediated partly through calcium signal.

Objective: Urinary bladder hyperplasia associated with terephthalic acid (TPA) treatment was examined with concomitant use of sodium bicarbonate (NaHCO3) or hydrochlorothiazide to allow assessment of the relationship among bladder stones,epithelial hyperplasia,and corresponding cell cycle checkpoint gene expression in Sprague–Dawley (SD)rat. Methods:A total of 112 weanling male SD rats that divided between six groups were given basal diet (control), diets containing 5% TPA or in combination with either 4% sodium NaHCO3 or 0.02% hydrochlorothiazide.After 90-day feeding,bladder samples were collected for histopathological diagnoses,and immunohistochemical method was used to characterize the expression of p16Ink4a,cyclin D1, CDK4, EGFr and cyclin E in relation to that of proliferating cell nuclear antigen (PCNA). Results:In TPA treatment groups, bladder stone incidence was 40% (21/52) with 14 cases of proliferative bladder.In control and other groups,neither stone nor epithelial cell proliferation was diagnosed.PCNA-positive focal hyperplasic lesions involved all epithelial layers.Overexpressions of cyclin D1, CDK4, EGFr are found in the corresponding lesion. p16Ink4a nuclear staining reduced in proliferative bladders especially with a great quantity of stone.In addition,no positive expression was detected on cyclin E. Conclusion: The present study provides a strong evidence of a link between induction of bladder hyperplasia, deregulation of the p16Ink4a-cyclin D1/CDK4 pathway,and abnormal EGFr mediated signal transduction pathway.

In this study,primary serum-free cultured rat granulosa cells (rGCs) were used as a cellular model to investigate the effects of fenvalerate on progesterone production. Various concentrations (0,1,5,25,125and625μM) of fenvalerate were added to the cell cultures for 24h.rGCs were stimulated by compounds such as follicle-stimulating hormone (FSH), 8-bromo-cAMP or 22(R)-hydroxycholesterol (22R-HC) Progesterone production and intracellular cAMP content were measured in control and treated groups.Expression of P450 side chain cleavage enzyme (P450scc) and steroidogenic acute regulatory protein(StAR)were monitored by real-time PCR and Western blotting.Results showed that fenvalerate inhibited basal progesterone production in rGCs in the absence of stimulators.This inhibition was stronger in the presence of FSH and was not fully reversed by 8-bromo-cAMP or 22R-HC.The increase of cAMP content,stimulated by FSH, was inhibited by fenvalerate implicating that the intracellular cAMP-dependent signal pathway was involved.Fenvalerate reduced mRNA and protein expression of P450scc.These results suggested that multi-site inhibition of progesterone production by fenvalerate including a cAMP-dependent protein kinase pathway and reduction on P450scc gene expression and/or its enzymatic activity in rGCs.

A cross-sectional study of 68 petrochemical workers(23had never smoked [E/NS],45 were current smokers [E/S]) and 130 subjects with no known history of exposure to petrochemicals (49 had never smoked [NE/NS], 81 were current smokers [NE/S]) was conducted to assess the effect of occupational exposure to petrochemicals and smoking on semen quality.In-person interviews revealed occupational history,smoking habit,and lifestyle.Semen parameters such as volume,viability,sperm forward progression rate,sperm density,and total sperm count were determined for all subjects.The results show that the E/NS workers had a lower sperm forward progression rate (P<0.05) compared with controls (NE/NS). Individuals in the NE/S group showed a significant inverse relationship between years smoked and sperm density (r=-.24,P<0.05). The data also revealed that cigarette smokers who had worked in a petrochemical plant had significantly poorer quality semen,including sperm density,total sperm count,and forward progression rate, compared with the control (NE/NS)group (P<0.01). Furthermore, there was a significant inverse correlation between combined exposure and smoking years,and sperm density (r=-.28, P<0.05). These findings suggest that occupational exposure to petrochemical compounds may aggravate the adverse effect that smoking has on semen quality.

Aims: To determine sperm nuclear DNA integrity and to investigate the relation between fenvalerate(FE)exposure and spermatozoa DNA damage. Methods: Sperm DNA fragmentation was detected by a modified alkaline single cell gel electrophoresis (Comet) assay and a terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL) assay. The olive tail moment (OTM) and percentage tail DNA were measured by the Comet assay, and cell positive percentage was measured by the TUNEL assay for DNA damage evaluation. Results: he DNA integrity of spermatozoa of external and internal control groups were both significantly greater than that of the FE exposed group. The median value of tail DNA percentage in the exposure group was 11.30, which was significantly higher than 5.60 in the internal control group and 5.10 in the external control group. The median value of OTM was 3.80 in the exposure group, significantly higher than 1.50 in the internal control group and 2.00 in the external control group.Mean cell positive was 31.2% in the exposure group, significantly higher than 17.4% in the internal control and 19.6% in the external control groups.Cell positive (%) was significantly correlated with tail DNA percentage and with OTM of whole subjects (n=63). Conclusions:Results showed that occupational FE exposure is associated with an increase in sperm DNA damage.A combination of the Comet and TUNEL assays would offer more comprehensive information for a better understanding of sperm DNA damage,and the biological significance of sperm DNA damage in sperm function and male infertility.