Effects of different levels of overworking on rat arterial smooth muscle cells

Abstract

Objective To determine the effect of overworking 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 the latter 2 groups, and the rats of the last group was subjected to sleep deprivation with an underwater platform. In 15 d 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 microscopy. The apoptotic rate of VSMC was detected by TUNEL, the mRNA expression of Caspsae-3, Bax, Bcl-2 and Ki67 in the VSMC were detected by RT-qPCR, and the content of apoptotic protein Caspase-3 was measured by immunohistochemical 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) 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 induces 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.

Keywords

• overworking
• arterial wall
• vascular smooth muscle cells
• apoptosis
• proliferation