The effects of thrombin on bovine aortic endothelial and smooth muscle cells

Abstract

Recent evidence suggests that thrombin interacts with various cell types, stimulating cellular proliferation and protein and prostanoid production. To further delineate its role in vascular healing, we have studied the effects of thrombin on proliferation and matrix production by the cells of the vessel wall. The addition of thrombin (1 unit/ml) to cultures of bovine aortic smooth muscle cells resulted in an increase in cell proliferation (p < 0.01) and number (p < 0.03), whereas in cultures of bovine aortic endothelial cells thrombin produced a decrease in cell proliferation (p < 0.01) and number (p < 0.02). Thrombin also altered matrix composition in cultures of these cells. In both bovine aortic endothelial cells and bovine aortic smooth muscle cell cultures grown in the presence of thrombin, total protein content was significantly increased when compared to controls (p < 0.03). In bovine aortic endothelial cell cultures the addition of thrombin resulted in a decrease in collagen content (p < 0.01) and an increase in sulfated glycosaminoglycan content (p < 0.02). In contrast, in bovine aortic smooth muscle cell cultures thrombin resulted in an increase in collagen content (p < 0.03), whereas glycosaminoglycan content was unaffected. These findings suggest that thrombin may significantly influence vascular healing and function by altering cell number and matrix composition.