Effect Of Acrylamide On The Expression Of PCNA, EGFR Protein In Rat Testicular Tissue And Its Mechanisms

ObjectiveTo investigate the effects of acrylamide on reproductive toxicity inmale rats, and the influence of expression of PCNA and EGFR in testiculartissues, to explore the mechanism of male reproductive toxicity induced byacrylamide.MethodsThirty-two SD male rats of5-6weeks old were randomly divided intocontrol group(distilled water),4mg/kg AA treatment group,12mg/kg AAtreatment group and36mg/kg AA treatment group. Thirty days afterintragastric administration, testes of rats were obtained, and the histologicalchanges of testicular tissues were observed with HE staining. The apoptosisof testicular cells was detected by TUNEL assay. The serum concentrationsof testosterone and estradiol were measured by chemiluminescent method.The expression of PCNA and EGFR mRNA in testicular tissues wasdetermined by RT-PCR. The expression of PCNA and EGFR protein intesticular tissues was examined by immunohistochemistry and Western blotting.ResultsThe body weight of rats in12mg/kg AA treatment group and36mg/kg AA treatment group was significantly lower than that in controlgroup(P<0.05). For12mg/kg AA treatment group and36mg/kg AAtreatment group, the numbers of spermatogenic cells in testicular tissueswere smaller, and there were atrophy of spermatogenic epithelia, vacuolesin lumina, and increased numbers of apoptotic cells. The serumconcentration of testosterone in each AA treatment group was significantlylower than that in control group(P<0.05), and the serum concentration ofestradiol in12mg/kg AA treatment group and36mg/kg AA treatmentgroup was significantly lower than that in control group(P<0.05). Theexpression of PCNA to tissues in12mg/kg AA treatment group and36mg/kg AA treatment group was significantly lower than that in controlgroup(P<0.05). The expression of EGFR mRNA in testicular tissues in12mg/kg AA treatment group and36mg/kg AA treatment group wassignificantly lower than that in control group(P<0.05). The expression ofEGFR protein in testicular tissues in each AA treatment group wassignificantly lower than that in control group(P<0.05).ConclusionExposure to AA may result in the decrease of sex hormone secretion,pathological changes of testicular tissues, increase of apoptotic cells and decrease of expression of PCNA and EGFR protein, which may interruptthe balance between proliferation and apoptosis of spermatogenic cells andlead to the functional impairment of reproductive systerm.