| Background:With development of living standard,the effects of obesity on the human health,especially on the problems of human reproduction caused by Alimeniary obesity (Simple obesity)have become the research hotspot. Lots of researches have proved that there is spontaneously the apoptosis of spermatogenic cells in rat testes, having obvious regularity. At the apoptotic early period, mitochondrial membrane transition pores open widely ,mitochondrial potential decreases, endocellular NOS enhances, ATPase activity decreases, Cyt c proteins in inter mitochondrial membrane release into endochylema, which activate the apoptotic relative factors and cause the cell apoptosis.In the paper, we measured the apoptotic situation of spermatogenic cells in rat testes and Cytc Cas-3 proteins changes with the methods on immunology, molecular biology and biochemistry in pubertal alimeniary obesity rats, and explored the mechanism that Cytc proteins participate in the regulation of spermatogenic cell apoptosis. At the apoptotic early period, the contents of endocellular ROS,NO,NOS and so on enhanced and cellular oxidative damage increased;there were the regularities in mRNA and protein expressions of apoptosis relative proteins Cyt c,AIF,caspase-3,which were similar to the testis spermtogenic cell apoptotic regularity. These results provide the essensial experiment basis for exploring the regulation mechanism that the mitochondria participate in the spermatogenic cell apoptosis of the pubertal alimeniary obesity rats.Cyt c locates center position in the cell apoptosis regulated by mitochondrial pathway. It activated caspase families in down stream, then the spermatogenic cell apoptosis happened. The caspase families were the important executor of apoptotic pathway. In this paper ,the changes of Cyt c,caspase-3 mRNA in rat testes were measured with PCR; the expressions of Cyt c and caspase-3 protein were measured with immunohistochemistry, respectively; Apoptosis was studied by light microscopy and TUNEL techniques.Objective:The establishment of diet-induced obesity model was given high-fat and high-calorie diet. To exploring the regulation mechanism that the mitochondria participate in the spermatogenic cell apoptosis of the pubertal alimeniary obesity rats.Method:Forty health male rats were divided randomly into a control group and a high-fat group. Normal Wistar rats was normal control group. The rats in control group (n=20) were fed on normal diet; the high-fat group (n=20) was given high-fat and high-calorie diet. The rats had been killed in ten weeks, and their testis had been obtained. Peripheral blood total cholesterol (TC), Triglyceride (TG), High-density lipoprotein cholesterol (HDL-C) and Low-density lipoprotein cholesterol (LDL-C) were detected by automatic biochemical analyzer (ACA). The changes of Cyt c,caspase-3 mRNA in rat testes were measured with PCR; the expressions of Cyt c and caspase-3 protein were measured with immunohistochemistry, respectively; Apoptosis was studied by light microscopy and TUNEL techniques.Result:1. The establishment of diet-induced obesity model: The rats in control group were fed on normal diet; the high-fat group was given high-fat and high-calorie diet. .The body weight in experimental group was higher 20% than that in control group at ten weeks old, Successfully established diet-induced obesity model.TC, TG, LDL-C and HDL-C (the high-fat group): 5.17±0.17, 1.18±0.09, 1.76±0.11, 5.08±0.18TC, TG, LDL-C and HDL-C (the control group): 1.38±0.12, 0.39±0.05, 0.97±0.07, 0.75±0.06Compared with the control group, the concentrations of TC,TG,LDL-C in the high-fat group increased dramatically and the levels of TC,TG,LDL-C decreased obviously(p<0.01).2. Pathological observation of rat testis: Under common circumstance, the spermatogonium nucleus in rat testes was big, euchromatin showed a grain shape, mitochondrial appearance was integrity; the spermatocyte heterochromatin was massive, its mitochondrial appearance was integrity; the spermatid nuclear chromatin was dense and uniformity, its mithchondrial appearance was integrity.With light microscope,the following phenomenon was manifestly detected: the sabotage of spermatogenic epithelium. the distance between spermatogonia and spermatocytes became long, their conjunction disappeared, the spermatocytes necrosed.3. Apoptotic cells in rat testis situation: The apoptotic index of spermatogenic cells in high-fat group (37.17±2.74) was definitely higher than the control group (5.16±0.81, P<0.01). The spermatogenic cells in apoptosis were mainly spermatogonia and spermatocytes.4. Rat testis in Cyt c,caspase-3 protein expression:The results in immunohistochemistry showed that caspase-3 positive spermatogonia increased significantly. The results in immunohistochemistry showed that Cyt c positive spermatogonia and spermatocytes tended to increase.The expression of Cyt c protein (162.53±8.77) in high-fat group was definitely higher than the control group (134.37±6.96, P<0.01). The expression of caspase-3 protein (155.83±6.62) in high-fat group was definitely higher than the control group (106.34±8.23, P<0.01).5. Rat testis Cyt c mRNA,caspase-3 mRNA expression: The expression of Cyt c mRNA (0.86±0.01) in high-fat group was definitely higher than the control group (0.49±0.02, P<0.01).The expression of caspase-3 mRNA(0.95±0.04)in high-fat group was definitely higher than the control group (0.39±0.03, P<0.01).Conclusion:1. Alimentary obesity can induce apoptosis of spermatogenic cells in testis increasing.2. Alimeniary obesity cause apoptosis of germ cell. Apoptosis of germ cell induced by Alimeniary obesity is mediated by Cytc,caspase-3 system.
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