Objective To observe the toxic effects of mercuric chloride (HgCl2) on the productive function of male mice with lower dosage exposune. Methods 4 week-aged male ICR mice were randomly divided into 3 exposure groups, and control group. The 3 exposure groups were treated with doses of 0.25, 0.50, 1.00 mg/kg HgCl2 by peritoneal injection respectively, one time per 3 days, 10 times in total. After exposure to HgCl2 for 50 days, the male mice were mated with female mice non-exposed to HgCl2 in a ratio 1∶2. The pregnant rate, number of pups whelped per group, body weight of offspring, testis index, sperm count, sperm motility rate, abnormal sperm rate were observed. Results The pregnant rates were 100%, 100%, 83.33% and 66.67% for control group, 0.25 mg/kg group, 0.50 mg/kg group and 1.00 mg/kg group respectively during 1-week conception, 100%, 100%, 83.33% and 75% for above corresponding groups respectively during 3-weeks conception respectively. The pregnant rate of 1.00 mg/kg group was significantly lower than that of control during 1-week conception (P

AIM: To explore the molecular mechanism of asthenospermia(AST) by preliminary screening of nucleotide sequences from the ND3 and ND4L genes of mitochondrial DNA(mtDNA). METHODS: Samples from 50 AST patients and 42 age-matched normal controls were collected according to the WHO criteria. Density gradient centrifugation was applied to separate spermatozoa with different vigor. The ND3 and ND4L genes of mtDNA were amplified and sequenced directly from the extracted genomic DNA from AST patients and normal controls. The sequences were compared with revised Cambridge Reference Sequence(rCRS) to analyze the variants. RESULTS: A total of 22 nucleotide variations were found in ND3 and ND4L genes of mtDNA in asthenospermia group and control group. G10320A, A10398G and T10609C were missense mutations, while A10157G and A10313C were the reported for the first time in this study. Haplotype N in patients with AST(33/50) was higher than that in control group(14/42, P<0.05), and haplotype R9 in patients with AST(15/50) was also higher than that in control group(4/42, P<0.05) through genetic testing of ND3 gene. Rates of sperm progressive motility of haplotype F1, F2 and R9 were significantly lower than those of haplotype M and M rest. Two haplotype differences, haplotype M and N, were found in the same AST patient's spermatozoas which had different vigor. Haplotype M had stronger vigor, while haplotype N had lower vigor. By sequencing ND3 gene of mtDNA from 50 AST patients, we detected G10310A heteroplasmic mutation in 2 specimens of asthenospermia with poor and moderate motility spermatozoa, respectively. No mutation occurred in good motility spermatozoa. CONCLUSION: Haplotype of mitochondrial may have some correlation with sperm motility. The nt10398G-10400T polymorphisms may have benefit for sperm motility, whereas the mutation in nt10310A may impair sperm motility.

Objective To investigate the relationship between mtND4 point mutation in sperms and asthenospermia. Methods Fifty-six asthenospermia cases and 44 control cases were collected using the WHO criterion for defining asthenospermia, the regions of mtND4 gene were amplified by using PCR of 3 pairs primers. Consequently, the point mutation, missense mutation and multiple single nucleotide polymorphisms (SNP) were analyzed by employing sequencing technology and bioinformatics tools. Results Six mutations never before identified were found. The frequency of single point mutation T10873C and T11944C in the control group were significantly higher than those in the asthenospermia group (P＜0.05). Eight cases involved T10873C or T11944C among the 10 cases in control groups with missense mutations were found. But, there were only 2 cases with such mutation in the 10 asthenospermia cases with missense mutations (P＜0.05). The previous 20 cases of missense mutations can be described as either multiple SNP group (with T10873C or T11944C) or nonmultiple SNP group. The percentage of a range and a plus b range of multiple SNP group of sperm was significantly higher than the non-multiple SNP group(P＜0.05). Conclusions mtND4 gene mutation, especially the missense mutation may induce loss of sperm motility. The mutations of T10873C and T11944C may be useful for sperm motility or counteract the influence for the sperm motility caused by these harmful mutations.

Objective This study was aimed to investigate the effects of ω-3 polyunstaurated fatty acids (ω-3 PUFAs) on the growth of gastric cancer cells in nude mice,and to find whether the Ros homolog gene Rho-associated coiled-coil containing protein kinase 1 (RHO-ROCK1) signaling pathway is involved.Methods 16 BALB/C nude mice were injected subcutaneously with SGC7901 gastric cancer cells to establish the tumor-bearing mouse model.The mice were randomized:control group (normal saline) and intervention group (ω-3 PUFAs).The mRNA expression of Ros homolog gene family,member A (RHOA),RHOC,and ROCK1 in tumor tissue were detected by quantitative polymerase chain reaction (qPCR).Immunofluorescence and Western blot were used to detect RHOA,RHOC,and ROCK1 protein expression.Results The volume and weight of the tumors in the ω-3 PUFAs group were slightly smaller than that in the control group (P ＞ 0.05).Compared to the control group,hematoxylin and eosin staining showed multifocal tumor necrosis in the ω-3 PUFAs group,while the tumors of the control group showed abundant blood supply.qPCR and Western blot showed that the mRNA and proteins expression of RHOA and ROCK1 in the ω-3 PUFAs group was significantly lower than those in the control group (P ＜ 0.05).The immunofluorescence redults also showed that the expression of these proteins in the ω-3 PUFAs group was slightly lower than that in the control group.Conclusions These results suggested that ω-3 PUFAs may affect the growth of gastric cancer in nude mice by affecting the expression of RHOA,RHOC and ROCK1,thus inhibiting the excessive proliferation of gastric cancer cells and leading to tumor necrosis.