| Objective: Molybdenum as a heavy metal element,is the only animal essential heavy metals trace elements,molybdenum deficiency and excess can cause adverse reactions of animals,due to the recent increase in molybdenum,molybdenum overdose lead to poisoning is more serious,the test passed to establish a different dose of molybdenum poisoning model to study the effect of high dose molybdenum on reproductive function in male rats and its mechanism.Methods: Forty healthy male Sprague-Dawley rats aged 6-8 weeks with similar body weight(about 180-200g)were randomly divided into 4 groups(n = 10).Strict control of dietary copper,molybdenum,sulfur,phosphorus and other elements of the proportion of the body to meet the normal needs of drinking deionized water,by adding different doses of molybdenum,the establishment of the test model: normal control group(0mg / kg Mo),Low dose Molybdenum(80 mg / kg Mo),medium dose molybdenum(100 mg / kg Mo)and high dose molybdenum(120 mg / kg Mo).On the 45 th day of the test,the rats were sacrificed by blood sampling,blood test,epididymis and other samples.The rats were treated with enzyme-linked immunosorbent assay(ELISA),HE staining and fluorescence quantitative PCR.The effects of high dose molybdenum on the reproductive function of male rats were studied at the structure,cell and molecular level.Result:1.Changes of body weight in male rats: The rats in each group were treated with different doses of molybdenum for 7 days,In the test group,the weight gain of the low dose molybdenum group was the highest,which was 6.08% higher than that of the control group(P<0.01).Followed by medium dose molybdenum group and high dose molybdenum group,the molybdenum group decreased by 4.44% and 2.54%,respectively,compared with the low molybdenum group and the molybdenum group(P<0.05),and the difference was significant(P<0.05).With the extension of exposure time,the weight gain of experimental group was significantly lower than the control group.The Compared with the control group,the body weight of low molybdenum group,molybdenum group and high molybdenum group decreased by 10.09%,24.67% and 29.11% respectively after exposure to 42d(P<0.01).The results showed that a certain dose Molybdenum elements can promote the growth of rats,and with the increase in intake time,excessive accumulation of molybdenum in the body lead to molybdenum poisoning,resulting in slow weight gain.2.Changes of testicular coefficients in male rats: Compared with the control group,the testicular coefficients of medium dose molybdenum group and high dose molybdenum group decreased by 8.02% and 13.65% respectively(P < 0.01);Compared with the low dose molybdenum group,the testicular coefficient of medium dose molybdenum group and high dose molybdenum group decreased by 4.57% and 10.37%(P<0.01);Compared with the medium Molybdenum group,the testis coefficient of the high dose molybdenum group decreased by 6.14%(P<0.01).3.Rat sperm density test results: The sperm density in the epididymis of rats decreased with the increase of molybdenum concentration.Compared with the control group,the sperm density in the epididymis of the low molybdenum group decreased by 6.28%(P<0.05),the medium dose molybdenum group and the high molybdenum group decreased by 6.28% by 23.17% and 51.95%(P<0.01).Compared with the low molybdenum group,the medium dose molybdenum group and the high molybdenum group decreased by 18.02% and 48.73%,respectively(P < 0.01);The high molybdenum group decreased by 37.46% than medium dose molybdenum group(P<0.01).4.Determination of sperm motility in rats: Compared with the control group,the low molybdenum group decreased by 6.34%(P < 0.05),the medium dose molybdenum group and the high molybdenum group decreased by 6.28% and 34.99% respectively(P<0.01);Compared with the medium dose molybdenum group,the high dose molybdenum group and the low molybdenum group decreased by 30.59% and 18.75% respectively(P<0.01).5.Determination of sperm abnormality in rats: The sperm deformity rate in the epididymis of the low dose molybdenum group,the medium dose molybdenum group and the high molybdenum group increased by 26.92%,65.90% and 101.28% than the control group(P<0.01);The high dose molybdenum group increased 58.59% compared with the low molybdenum group(P<0.01).Compared with the medium dose molybdenum group,the high dose molybdenum group increased by 21.33%(P<0.05).6.HE staining of testis tissue showed: In the normal control group,the seminiferous tubules were arranged neatly and the basement membrane was intact and the spermatocytes were arranged at all levels.Leydig cells form normal,there are a large number of sperm in the bureaucracy.Low-dose molybdenum testicular tissue seminiferous tubules morphology,normal structure,compared with the control group no significant morphological changes,only a small amount of spermatogenic cell degeneration and apoptosis phenomenon.The morphological changes of the seminiferous tubules in the medium-dose molybdenum group were significantly decreased,the number of spermatogenic epithelium decreased,the number of spermatocytes and the number of supporting cells decreased,the gap increased,the disorder was arranged,the vacuoles were obvious,Only found a small amount of mature sperm.High-dose molybdenum group fine seminiferous tubule structure is seriously damaged,spermatogenic cells,support cells and stromal cells degeneration and necrosis increased significantly,vacuolization and degree is extremely significant.7.Test results of rat serum testosterone: Compared with the control group,the serum testosterone content in the low molybdenum group decreased by 15.36%(P<0.05).The serum testosterone content in the medium dose molybdenum group and the high dose molybdenum group decreased by 48.89% and 74.42% respectively,(P<0.01).;The serum testosterone content in the high molybdenum group decreased by 49.94% and 69.77% than medium dose molybdenum group and the low dose molybdenum grouplow(P<0.05).8.Testosterone antioxidant enzymes and oxidation products Determination results: Compared with the control group,the activity of T-SOD of low dose molybdenum group decreased by 5.03%(P<0.05),and the content of T-SOD in the medium dose molybdenum group and the high dose molybdenum group decreased by 35.07% and 60.02%;Compared with the low dose molybdenum group,the activity of T-SOD decreased by 31.63% and 57.75%(P<0.01),respectively,in the medium dose molybdenum group and the high dose molybdenum group.The T-SOD in the testes of the high dose molybdenum group decreased by 38.43% than medium dose molybdenum group(P<0.01).The content of MDA in testes was the highest in high dose molybdenum group.Compared with the control group,the content of MDA in the testes of the low dose molybdenum group increased by 11.69%(P<0.05);Compared with the control group,the content of MDA in the testes of the medium dose molybdenum group and high dose molybdenum group increased by 46.43% and 90.24%(P<0.01).The medium dose molybdenum group and the high molybdenum group increased by 31.10% and 70.29% than low dose molybdenum group(P<0.01).Compared with the medium dose molybdenum group,the content of MDA in the testes high dose molybdenum group 29.89%(P<0.01).9.Anticozyme and lipid peroxidase mRNA expression in testis tissue: Compared with the control group,the expression of SOD in the testes of the medium dose molybdenum group and high dose molybdenum group decreased by 63.07% and 83.88%(P<0.01).;The the medium dose molybdenum group decreased by 46.47% than low dose molybdenum group(P<0.01);The high molybdenum group decreased by 76.64% and 56.35%(P<0.01),respectively,compared with the low dose molybdenum group and the medium dose molybdenum group.Compared with the control group,the expression of the low dose molybdenum group of GSH-Px in the testes decreased by 34.21%(P<0.05),while the medium dose molybdenum group and the high dose molybdenum group decreased 61.21% and 75.76%(P<0.01);Compared with low dose molybdenum group and medium dose molybdenum group,the high dose molybdenum group decreased by 63.16% and 37.52%(P<0.01).Compared with the control group,the expression of LPO in the testes was 60.55%,120.94% and 183.39% in the low molybdenum group,medium molybdenum group and high molybdenum group respectively(P<0.01);Compared with the low molybdenum group,the medium molybdenum group increased by 37.62%(P<0.01),and the high molybdenum group increased by 76.51%(P<0.01).The high dose molybdenum group increased 28.26% than medium dose molybdenum group(P<0.05).10.Testosterone synthesis of testosterone related enzyme gene mRNA expression of the results: The expression of P450 scc in the testes of low molybdenum group,medium molybdenum group and high molybdenum group decreased by 47.20%,64.94% and 77.25%(P<0.01)respectively compared with the control group.Compared with the low molybdenum group,the medium molybdenum group and high molybdenum group decreased by 33.60% and 59.92%,respectively(P<0.01).The high molybdenum group decreased by 35.12% than medium molybdenum group(P<0.01).Compared with the control group,the expression of P450c170 in the testes of low molybdenum group decreased by 29.05%(P<0.05),medium molybdenum group and high molybdenum group decreased by 71.09% and 86.45% respectively(P<0.01).Compared with the low dose molybdenum group and medium molybdenum group,the high dose molybdenum group decreased by 80.90%,and 53.12% respectively,(P<0.01).Compared with the control group,the expression of 17?-HSD in low molybdenum group,medium molybdenum group and high molybdenum group decreased by 34.58%,66.36% and 88.79%,respectively(P<0.01);Compared with the low molybdenum group,the medium molybdenum group and high molybdenum group decreased by 48.58% and 82.86%,respectively(P < 0.01).The high molybdenum group decreased by 66.67% than medium molybdenum group(P<0.01).There was no significant difference in the expression of 3 ?-HSD and the low molybdenum group in the testis group compared with the control group.The medium molybdenum group increased by 11.33% than low molybdenum group(P<0.01).The high molybdenum group decreased by 34.11% and 37.05% than the control molybdenum group and medium molybdenum group respectively(P<0.01);The high molybdenum group increased by 29.91% than low molybdenum group(P<0.01).In conclusion: High dose of molybdenum(120 mg / kg Mo)resulted in a large number of harmful peroxidation products,severe consumption of antioxidant enzymes in the body;severe damage to the testis tissue of rats,destruction of the normal morphology of the testicular tissue,and inhibition of testosterone production gene expression,the testosterone content significantly reduced sperm quality decreased,and ultimately affect the reproductive function of rats. |
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