Objective: To study the occurrence of vascular calcification in aged rats, and the changes of osteopontin and osteocalcin expression in the arterial vessel wall of aged rats.
METHODS: Twenty 20-month-old SD rats were selected as the experimental group, and 20 3-month-old SD rats were selected as the control group, and the aortic strips, heart and kidney tissues of the rats were collected for examination. The morphology of blood vessels was observed by HE staining, the degree of calcium deposition was determined by Von Kossa staining, and the expressions of OPN and OC in the blood vessel wall were determined by immunohistochemistry and Western-blot.
Results: The vascular smooth muscle cells in the experimental group were disordered, the thickness of the media layer increased, the elastic plate was broken, and the degree of vascular fibrosis was increased; in the control group, the intimal endothelial cells and vascular smooth muscle cells were neatly arranged, and the elastic plate was intact. Calcium deposits were found in the large arteries and micro-arteries of rats in the experimental group, but no calcium deposits were found in the arteries of the control group. The expressions of OPN and OC in the blood vessel wall of rats in the experimental group were significantly up-regulated compared with those in the control group (P<0.05).
Conclusion: Vascular media calcification may be the pathological manifestation of vascular aging, and the formation of vascular calcification may be related to the up-regulation of bone formation-related proteins OPN and OC.