| Cadmium is a non-essential element of the organism.When few cadmiumenter into the body,it will lead to kidney,liver,lung,pancreas,testis,placenta and bone,including various organs irreversible damage.Cadmium can produce reproductive toxicity in male animals or humans,and results in cell apoptosis or necrosis.Testicular tissue is the role of the target organ.Therefore,it is of great theoretical and practical significance to explore the mechanism of cadmium-induced apoptosis in rat.In this study,rat testicular sertoli cells were isolated and cultured in vitro.The effects of different concentrations of cadmium on the cell proliferation rate were identified by method of HE staining,oil red O and Feulgen staining.The different concentrations of cadmium effects on the changes of SOD activity and MDA content in the cells were examined.The ultrastructural changes were observed by transmission electron microscopy.The apoptosis of the cells were induced by different concentrations of cadmium by flow cytometry.RTFQ-PCR was used to detect the expression of Bax,Bcl-2,Cyt-C,AIF,Caspase-3 and Caspase-9 mRNA in the sertoli cells.In vitro culture of isolated cell morphology sertoli cells were oval,and grow a number of protrusions,nucleolus and cytoplasmic particulate matter.Sertoli cells after HE staining,were irregular shape or radial andhad a number of thick protrusions,and cell nuclei was dyed dark,cytoplasm was dyed red.The nucleus were stained blue after oil red O staining,lipid dropletspresented in cytoplasm.The cytoplasm was not colored in Feulgen staining,and the stained nucleus possessed purplewith a few to the darker colored red particles that can be seen around the satellite body.When the concentration of cadmium chloride(0,10,20,40,80μmol/L)was servered as sertoli cells for 24 h,the changes of cell cycle rate,SOD activity and MDA content were detected.With the increase of cadmium chloride concentration,the reproductive rate of each test group decreased,and cadmium chloride on testicular support cell reproductive rate had dose-dependent and statistically significant.SOD activity and MDA content increased with the increase of cadmium chloride concentration,what showed a dose-effect relationship.The result of the transmission electron microscopy showed that the organelles in the control group were clear and complete,and the mitochondria were clearly visible.The cytoplasm contained lipid droplets and had many fat vacuoles.Early apoptoticsertoli cells,mitochondria swelling,steep fracture,ribosome and mitochondrial aggregation decreased,but most of the organelles structural integrity,increased endoplasmic reticulum.The apoptotic cells in the medium-term apoptotic cells began to cleave into dense,compact bodies with multiple membrane structures and concentrated by chromatin.Late apoptotic sertoli cells had a large number of vesicular structures,and were isolated from the main cells and formed apoptotic bodies in which organelles were observed.The results offlow cytometry showed that the degree of apoptosis gradually increased with the increase of cadmium chloride concentration.The early apoptosis rate of 10μmol/L cadmium chloride challenge group was 12.76%,which was not significantly different from that of the control group.The apoptosis was significant difference among 20,40 and 80μmol/L cadmium chloride challenge group,and the result showed a concentration-dose relationship.The early apoptotic cells decreased and the advanced apoptotic cells increasedto 83.30% in 80μmol/L cadmium chloride challenge group.The early and mid-term apoptosis were mainly expressed in low and medium concentrations of cadmium,while the sertoli cells displayed late apoptosis in highconcentrations of cadmium-induced.The expression of Bax,Cyt-C,AIF,Caspase-3 and Caspase-9 was up-regulated in vitro,and had a significant dose-effect.In addition to,the expression level of Bcl-2gene increased by RTFQ-PCR relationship.The results showed that cadmium could regulate the mitochondrial conduction pathwayrelated genes and induce apoptosis. |
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