Apoptosis in the testis has two putative roles during normal spermatogenesis; limitation of the germ cell population to numbers that can be supported by the Sertoli cells, and, possibly, selective depletion of meiotic...Apoptosis in the testis has two putative roles during normal spermatogenesis; limitation of the germ cell population to numbers that can be supported by the Sertoli cells, and, possibly, selective depletion of meiotic and postmeiotic abnormal germ cells. We investigated the demographic and biological correlates of the pro-apoptotic marker Fas and the anti-apoptotic marker Bcl-xL in sperm cells of fertile men. Six hundred and four men from Greenland, Poland and Ukraine were consecutively enrolled during their pregnant wife＇s antenatal visits. Semen analysis was performed as recommended by the World Health Organization. Immunofluorescence coupled to flow cytometry was utilized for detection of apoptotic markers in the sperm cell. DNA damage was assessed by flow cytometry using both the sperm chromatin structure assay （SCSA） and the terminal deoxynucleotidyl transferase dUTP nick end labelling （TUNEL） assay. The percentage of Fas-positive sperm cells was higher in men with high total sperm count （P〈O.01）, more motile sperms （P=-O.04） and fewer sperm head defects （P=-O.05）. These associations were consistent within and across study regions. Furthermore, testosterone, follicle-stimulating hormone （FSH） and sexual hormone-binding globulin （SHBG） were significantly negatively correlated with Fas within and across regions as well. The data indicated no association between the anti-apoptotic Bcl-xL marker and semen or personal characteristics. The finding of Fas-positive sperm cells associated with better semen quality in a cohort of spouses of pregnant women seems different from previous data obtained in infertile men and warrants further investigation to clarify the biological significance of sperm apoptotic markers.展开更多
Several animal studies indicate that mercury is a male reproductive toxicant, but human studies are few and contradictory. We examined semen characteristics and serum levels of reproductive hormones in relation to env...Several animal studies indicate that mercury is a male reproductive toxicant, but human studies are few and contradictory. We examined semen characteristics and serum levels of reproductive hormones in relation to environmental exposure to mercury. Blood and semen samples were collected from 529 male partners of pregnant women living in Greenland, Poland and Ukraine between May 2002 and February 2004. The median concentration of the total content of mercury in whole blood was 9.2 ng ml-1 in Greenland （0.2- 385.8 ng ml-1）, 1.0 ng m1-1 in Poland （0.2-6.4 ng ml-z） and 1.0 ng ml-I in Ukraine （0.2-4.9 ng ml-1）. We found a significantly positive association between the blood levels of mercury and serum concentration of inhibin B in men from Greenland （p=0.074, 95% confidence interval （CI）=0.021 to 0.126） and in an analysis including men from all three regions （p=0.067, 95% C1=0.024 to O. 110）. The association may be due to beneficial effects of polyunsaturated fatty acids （PUFAs）, which are contained in seafood and fish. No significant association （P〉O.05） was found between blood concentrations of mercury and any of the other measured semen characteristics （semen volume, total sperm count, sperm concentration, morphology and motility） and reproductive hormones （free androgen index {FAI）, follicle-stimulating hormone （FSH）, luteinizing hormone （LH）, testosterone and LH xtestosterone） in any region. In conclusion, the findings do not provide evidence that environmental mercury exposure in Greenlandic and European men with median whole blood concentration up to 10 ng m1^-1 has adverse effects on biomarkers of male reproductive health.展开更多
文摘Apoptosis in the testis has two putative roles during normal spermatogenesis; limitation of the germ cell population to numbers that can be supported by the Sertoli cells, and, possibly, selective depletion of meiotic and postmeiotic abnormal germ cells. We investigated the demographic and biological correlates of the pro-apoptotic marker Fas and the anti-apoptotic marker Bcl-xL in sperm cells of fertile men. Six hundred and four men from Greenland, Poland and Ukraine were consecutively enrolled during their pregnant wife＇s antenatal visits. Semen analysis was performed as recommended by the World Health Organization. Immunofluorescence coupled to flow cytometry was utilized for detection of apoptotic markers in the sperm cell. DNA damage was assessed by flow cytometry using both the sperm chromatin structure assay （SCSA） and the terminal deoxynucleotidyl transferase dUTP nick end labelling （TUNEL） assay. The percentage of Fas-positive sperm cells was higher in men with high total sperm count （P〈O.01）, more motile sperms （P=-O.04） and fewer sperm head defects （P=-O.05）. These associations were consistent within and across study regions. Furthermore, testosterone, follicle-stimulating hormone （FSH） and sexual hormone-binding globulin （SHBG） were significantly negatively correlated with Fas within and across regions as well. The data indicated no association between the anti-apoptotic Bcl-xL marker and semen or personal characteristics. The finding of Fas-positive sperm cells associated with better semen quality in a cohort of spouses of pregnant women seems different from previous data obtained in infertile men and warrants further investigation to clarify the biological significance of sperm apoptotic markers.
文摘Several animal studies indicate that mercury is a male reproductive toxicant, but human studies are few and contradictory. We examined semen characteristics and serum levels of reproductive hormones in relation to environmental exposure to mercury. Blood and semen samples were collected from 529 male partners of pregnant women living in Greenland, Poland and Ukraine between May 2002 and February 2004. The median concentration of the total content of mercury in whole blood was 9.2 ng ml-1 in Greenland （0.2- 385.8 ng ml-1）, 1.0 ng m1-1 in Poland （0.2-6.4 ng ml-z） and 1.0 ng ml-I in Ukraine （0.2-4.9 ng ml-1）. We found a significantly positive association between the blood levels of mercury and serum concentration of inhibin B in men from Greenland （p=0.074, 95% confidence interval （CI）=0.021 to 0.126） and in an analysis including men from all three regions （p=0.067, 95% C1=0.024 to O. 110）. The association may be due to beneficial effects of polyunsaturated fatty acids （PUFAs）, which are contained in seafood and fish. No significant association （P〉O.05） was found between blood concentrations of mercury and any of the other measured semen characteristics （semen volume, total sperm count, sperm concentration, morphology and motility） and reproductive hormones （free androgen index {FAI）, follicle-stimulating hormone （FSH）, luteinizing hormone （LH）, testosterone and LH xtestosterone） in any region. In conclusion, the findings do not provide evidence that environmental mercury exposure in Greenlandic and European men with median whole blood concentration up to 10 ng m1^-1 has adverse effects on biomarkers of male reproductive health.
