Effects Of Different Levels Of Overworking On Rat Arterial Smooth Muscle Cells

Objective: To study the effect of overwork on vascular smooth muscle cells（VSMC）in rats.Methods: Clean SD rats were randomly divided into control group（CON）,overworking group（OW）and overworking and sleep deficiency group（OW+SD）.The rat model of overworking was established by exhaustive swimming in group OW and OW+SD,and the rats of the group OW+SD was subjected to sleep deprivation with an underwater platform.In 15 days later,the abdominal aorta of rats was collected for pathological observation by HE staining,and the thickness of media was measured with aid of Image J software.The intracellular ultrastructure was observed by transmission electron microscope.The apoptosis rate of VSMC was detected by TUNEL,the m RNA expression of Caspsae-3,Bax,Bcl-2 and Ki67 in the VSMC were detected by RT-q PCR,the content of apoptotic protein Caspase-3 was measured by immunohistochemistry assay.Results:（1）The results of HE staining showed that VSMC were in disordered arrangment and formed vacuole-like cells in the OW and OW+SD groups,and the vascular intima-media thickness was significantly thicker in the OW and OW+SD groups than the CON group（P<0.05）.（2）Electron microscope displayed the apoptotic bodies in VSMC of the OW and OW+SD groups.（3）TUNEL results showed that the apoptotic rate of VSMC was significantly in the OW and OW+SD groups than the CON group（P<0.05）.（4）RT-q PCR showed that the expression levels of Bax and Ki67 were significantly increased（P<0.05）,while those of Caspase-3 and Bcl-2 was not obviously changed in the OW and OW+SD groups（P>0.05）when compared with the CON group.（5）Immunohistochemical results showed that the protein content of Caspase-3 in vascular middle membrane of the OW and OW+SD groups was increased significantly than that in the CON group（P<0.05）.Conclusion: Overworking aggravates the apoptosis of VSMC and induce the proliferation and repair of VSMC,which form the pathological basis of early arterial lesions.During the experimental time,sleep could not alleviate the injury of VSMC caused by overworking.