| In recent years, male infertility problems present a trend of increasing incidence rates. Clinical investigations also revealed that the environmental factors and nephritic disease which render sperm abnormal and infertile increased significantly. The molecular study on the maturation of sperm has a bright promise in the field of clinical practice. Normally, sperms in spermatogenic small tube have already been highly differentiated but not fully mature yet. They pass through epididymal lumen, interacting with epididymal duct microenvironment, and finally acquiring the capacity for forward motility and the ability to fertilize. Epididymis are composed of four parts: initial segment, caput, corpus and cauda, which connects with seminal duct.. Epididymis secreted proteins which participated in acrosome reaction, sperm-egg recognition, fusion at sperm plasma membrane and regulated sperm maturation and capacitation. It has been reported that human seminal plasma (mixtures of male genital duct secreting proteins, glycoprotein, peptide etc) contains high concentration of free oligosaccharides (0.3-0.4mg/ml) rich in fucose carried Le~X and Le~Y epitopes and abundant fucosyltransferase , assuming that free oligosaccharides may be involved in strengthen the ability for sperm forward motion, promoting sperm binding to eggs in oviduct and increasing immunosuppressive activity of sperm.Lewis oligosaccharides are fucosylated lactose series oligosaccharides, including Le~X,Le~Y,Le~a,Le~b sLe~X etc. The different between Le~X and Le~Y only lies in extreme oligosaccharide Fucα1-2. Lewis oligosaccharides are related to development, organ formation,hematopoietic cell differentiation and tumour cell diversion. We have studied Le~Y oligosaccharide function at female reproductive system and found that the antigen consecutively was highly expressed on the endometrium of implantation stage and blastocyst. It might act as signal molecule participating in recognition, adhesion of uterus-embryo and regulating implantation by ovarian hormone. Genes of the key enzyme (fucosyltransferase, FUTs), which catalyze Lewis oligosaccharides synthesis showed the same enriching tendency with Lewis oligosaccharides carried proteins. The results suggest that Le~X and Le~Y synthesis are regulated by key enzyme gene FUTs.Cadmium as rubber, batteries, cigarettes, the important ingredients of fertilizer, is known in the most vulnerable in the accumulation of environmental toxicology. Most researches have shown that a small amount of Cadmium in the body can cause great toxicity to organs, especially the testicle and its cells by the bioenlargement and bioaccumulation effect. Nephritic diseases are aroused due to abnormal kidney excretion, endocrine, immune and metabolic functions,and bring about a series of pathophysiological changes, leading finally to lesions in other organs. The establishment of animal models of kidney disease, can be helpful to the research of disease.There are two animal models in this experiment: one is using Cadmium Chloride to simulate the injury caused by the chemical pollution, the other is using the adenine to simulate CRF. The differences of secretion and expression of Le~X and Le~Y glycoprotein in the epididymis in normal condition and these two pathological conditions are compared.After the general analysis of the death rate ,the change of weight, the histology modality and physiological detection, we found that the ideal C57 model group is 1.5 mg/kg.RT-PCR analysis:In cadmium group, the mRNA levels of the key enzymes including fut9, fut1 and fut4 composed by Le~X and Le~Y in caput, corpus, the cauda of the epididymis in the experiment group were lower than those of the comparison group. Cadmium may inhibit the expression of the key enzymes composed by Le~X and Le~Y.Immunohistochemistry detection:In Cadmium Chloride group: Le~X had no expression in both experimental group and control group, in the experimental group, the Le~X in caput of epididymis was mainly found in the secretion of the duct; in the comparison group, the Le~X in caput of epididymis mainly expressed on the main cells. The expression of Le~Xin corpusand the cauda of the experiment group is lower than that of the control group. Le~Y showed the similar distribution as Le~X. The Analysis showed that cadmium rendered the expression of Le~X and Le~Ydecreased.In adenine group: Le~X in the testes in each group were negative; the Le~X expression in the caput of the epididymis of the experimental group were mainly distributed in the wall and the lumen in the secretion, and the control group were mainly distributed in the wall Le~X in the experimental group of corpus, cauda is higher than the control group. The positive expression of the Le~Y in the testes was not detected.There is no remarkable difference between experimental group and control group in the expression of the Le~Y, only the protein quantity a little higher in the experimental group.Western blot:In Cadmium Chloride group: the quantitative trends of protein expression of Le~X and Le~Y in the experiment group were the same; the results of the experiment group were lower than that of the comparison group.In adenine group: both Le~Xand Le~Y were expressed in the epididymis caput, corpus, the cauda and testicle. The protein amount of Le~X and Le~Y in the experimental group is higher than that of the comparison group.These results suggest that, sperm quantity and quality in cadmium model gruop and adenine model group changed with the derangement of oligosaccharides secretion. This result also provides further evidence on environmental impact of the epididymis glycoprotein on sperm maturation,the specific mechanism of which is still under exploration. |
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