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Objective To investigate the effect of long term low-dose manganese exposure on testicular spermatogenic cell mitochondria morphology and apoptosis of male offspring rat.Methods Thirty-two healthy female SD rats were divided into the control group,low,middle and high dose groups.2,4 and 8 mg/kg MnCl2 · 4H2 O or normal saline was intraperitoneally injected for 8 weeks(once daily,5 d/week).The manganese exposure continued during the pregnant period and lactation period.Eight 12-week-old offspring male rats were killed in each group,the structure of seminiferous tubules and mitochondria morphology in spermatogenic cells were observed.The expression of Opa1,Drp1 and Caspase9,and the apoptosis of spermatogenic cells were detected.Results With the increase of administered-MnCl2 dosage,the number of spermatogenic cell layers decreased,spermatogenic cells arranged in disorder,the number reduced,etc;the mitochondria separation and swelling of spermatogenic cells were found in the middle and high dose groups;the expression of Opa1 was gradually decreased in the middle and high dose groups(P＜0.05,P＜0.01),while the expression of Drp1 and Caspase9 was gradually increased with the manganese dose increase(P＜0.05,P＜0.01);the apoptotic index of spermatogenic cells in the manganese exposure group was significantly increased with the increase of administeredMnCl2 dosage(P＜0.05).Conclusion Long term low dose of manganese exposure could regulate the expression of Opa1/Drp1 gene and affect the function of mitochondria,leads to apoptosis of spermatogenic cells in male offspring rat.
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Objective To investigate the effect of chronic low-dose manganese chloride exposure on cell cycle and apoptosis of spermatogenic cells in offspring rat. Methods 32 healthy female SD rats were randomly divided into control and manganese exposure groups(n=8).The manganese exposure group respectively received 2,4 and 8 mg/Kg MnCl2·4H2O,while the control group was treated with equal volume saline for 8 weeks(1 time/d,5 d/w).After mating with normal male SD rats and determining conception,female rats were continued to be ex-posed to manganese during pregnancy and lactation. There were. 8 offspring male rats in each group. In the 12th week,the offspring rates were randomly executed and their testes were used to observe the structure of seminifer-ous tubules by HE staining. The expression of FOXO3A,cell cycle associated proteins P16,P21,CDK2, CDK4,CDK6 and apoptosis related proteins BIM,Caspase-9 in the testis of offspring male rats were detected by western blotting. In addition,the apoptosis of spermatogenic cells was detected by TUNEL. Results(1)With the increase of administered-MnCl2 dosage,the seminiferous tubule showed various changes,including layers of spermatogenic cell decreased,spermatogenic cells arranged in disorder,the number of mature sperm in the lumen of seminiferous tubule significantly reduced.(2)The expression of FOXO3A,P16 and P21 increased while CDK2 and CDK4 decreased gradually with the increase manganese exposure dose. CDK6 expression was not significantly changed in all groups.(3)The expression of BIM,Caspase-9 and apoptotic index of spermatogen-ic cells increased gradually with the increase of manganese dose. Conclusion Chronic low-dose of manga-nese exposure could induce expression of FOXO3A,further cause cell cycle arrest and apoptosis of spermatogen-ic cells in offspring rat.
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Objective To study the antagonism of glutathione(GSH) to antioxidative capacity decrease induced by manganese exposure in rats.Methods 48 healthy male SD rats were randomly divided into six groups: the blank control,GSH control,MnCl2.4H2O(15 mg/kgand 30 mg/kg),15 mg/kgMnCl2.4H2O+1 mmol/kgGSH and 30 mg/kg MnCl2.4H2O+1 mmol/kg GSH,the treatment was conducted through peritoneal injection.The activity of superoxide dismutase(SOD),catalase(CAT) and glutathione peroxidase(GSH-Px)in the serumand the testis were determined bycolorimetric analysis.Results Compared with the blank control group,the activity of SOD,CAT and GSH-Px in the serum and testis in 30 mg/kg groups significantly decreased(P
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Objective To study the effect of manganese chloride on apoptosis,p53 and Bcl-2 expression in the spermatogenic cells of rats.Methods 24 healthy male SD rats were randomly divided into three groups.Two groups were treated with MnCl2?4H2O through intraperitoneal injection at 15 mg/kg and 30 mg/kg respectively,once a day and 5 times in a week for four weeks,the third group served as the control and given normal saline.The spermatogenic cell apoptosis was examined by transmission electronic microscope and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL)technique.Expression of p53 and Bcl-2 were measured with immunohistochemistry.Results The apoptosis index(AI)and p53-positive-cell rate in manganese exposed group were significantly higher than those in the control group(P
