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.