| Purpose：Acrylamide (AA) is a white crystalline chemicals, and as afeedstock for the production of polyacrylamide, belonging to a kind ofenvironmental estrogens, widely used in the manufacture of water solublepolymer and organic chemicals.Everyday life, a high temperature (>120℃)under cooking, starchy foods is very easy to produce acrylamide. Humanabsorption acrylamide through a variety of channels, such as the digestivetract, respiratory tract, skin and mucous membrane[1], which gastrointestinalabsorption fastest.Fetuses and infants can also absorb acrylamide through theplacenta and breast milk. As early as the1980s，scientists had for the toxicityof acrylamide with a full understanding, About the neurotoxicity ofacrylamide，scientists had known that can cause such as drowsiness, memoryloss, insomnia, hallucinations etc, acute poisoning can be caused delayedperipheral nerve changes, such as unsteady gait, glove-like changes, weaknessetc. April2002, Swedish scientists first reported heated under hightemperatures, acrylamide found in starchy foods, acrylamide attracted theattention of scientists from various countries around the world once again. Inaddition to the neurotoxicity, Acrylamide contains carcinogenic, embryonicdevelopmental toxicity and reproductive toxicity[2]. Acrylamide has beenincluded in the International Research on Cancer (IARC) in Group2A “humanpotentially carcinogenic substances "[3]. Acrylamide reproductive toxicityembodied in many ways, some people think that acrylamide might will beinduced germ cell chromosomal mutation occurs; also someone think,acrylamide likely will affect testicular gene expression, resulting in the classof steroid hormone transporters and sperm occurred appeared abnormal, at thesame time, acrylamide also reduce the testosterone levels in the body. In spite of scientists on the reproductive toxicity of acrylamide make a lot ofassumptions, but still can not describe the mechanism completely, therefore,Reproductive Toxicology of acrylamide remains to be further elucidated.Telomerase is a ribonucleoprotein enzyme reverse transcriptase as atemplate the DNA sequence of the end of the de novo synthetic chromosometelomeres to its own endogenous RNA sequences. Closely related totelomerase activity in the cells of the proliferative potential of the cell cycle,cell differentiation, apoptosis and death. Most cells in the body is notelomerase activity, but telomerase activity in stem cells, germ cells and90%of the tumor cells can be found. Therefore, at present, telomerase as a cellproliferation indicators of a wide range of applications. Among the germ cells,telomerase activity to ensure the telomere DNA sequence consistently save, soas to ensure the split of germ cell DNA orderly, stable and inherited to the nextgeneration. As DNA polymerase δ accessory protein PCNA is required in theprocess of DNA replication and maintain DNA polymerase activity appearspeaked early in the G1, S phase, G2phase began to weaken, M disappeared,has been recognized to reflect state marker of cell proliferation. Of acrylamidethe spermatogenic cells telomerase activity and expression of PCNA impact toprovide some scientific basis for further study of the reproductive toxicity ofacrylamide.Materials and Methods:1Packet:40healthy male SD rats, weighing150to200g, wererandomly divided into four groups, the low-dose group (20mg/kg), middledose group (40mg/kg), high dose group (60mg/kg), negative control group(distilled water). Once-daily, weekly continuous application of5d, for twoweeks in a row.2Infected method and Detection indicators: animals in each group wereusing oral gavage, intragastric volume of0.01ml/g. Cervical dislocation14dafter the initial exposure killed, each rat testis and epididymis. Telomerasereverse transcriptase activity in rat spermatogenic cells and PCNA expressionby immunohistochemistry methods. 3Indicators of statistical processingResult:1Testicular tissue pathology test results:The control group testicularseminiferous epithelium cell arrangement rules, the basic rules of the low-dosegroup spermatogenic epithelial cells arranged, in the medium and high dosegroup spermatogenic epithelial cell layers reduce, spermatogenic cells wereseen in reduced in mature sperm in the lumen, the tubecavity larger, maturereduced sperm count, loose organizational structure.2Epididymal sperm density measurement results: the rat epididymal’ssperm density decreases with increasing acrylamide dose, medium and highdose groups were significantly decreased, and the difference was statisticallysignificant (P <0.05)3The spermatogenic cells telomerase expression measurement results:The control group telomerase reverse transcriptase (TERT) activity wasexpressed mainly in spermatogonia and spermatocytes higher. The low dosegroup with the control group telomerase reverse transcriptase (TERT)expression has decreased, but the positive products average absorbancedifference was not statistically significant (P>0.05). In the medium and highdose group rat spermatogenic cells TERT positive products significantlyreduced the mean absorbance of the positive products with the control group,the difference was statistically significant (P <0.05).4The spermatogenic cells PCNA expression measurement results: Thecontrol group of proliferating cell nuclear antigen (PCNA) activity wasexpressed mainly in spermatogonia and spermatocytes higher. The low dosegroup with the control group PCNA expression decreased, but the positiveproduct of the average absorbance difference was not statistically significant(P>0.05). In the medium and high dose group rat spermatogenic cells PCNApositive products significantly reduced the mean absorbance of the positiveproducts with the control group, the difference was statistically significant (P<0.05).Conclusion: 1Acrylamide can cause SD rat epididymal sperm density decreased.2Acrylamide can cause reduced expression of SD rat spermatogenic cells TERT.3Acrylamide can cause reduced expression of SD rat spermatogenic cells PCNA.4Acrylamide by reducing the SD rat spermatogenic cells expression ofTERT, PCNA, resulting in germ cell proliferation-apoptosis balance ofdestruction, thereby causing the formation of sperm obstacles, causingreproductive toxicity. |
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