Abstract
The mesenteric arteries of hypertensive rats with bilaterally constricted renal arteries showed severe arterial lesions with deposition of fibrinoid substance in the intima and severe medial cell injury. Scanning electron microscopic examination of these arteries revealed neutrophil adhesion to endothelial cells, and endothelial cell injury.
Immunohistochemically, ICAM-1, IL-1α, IL-6, IL-8 and TNF-α expression by endothelial cells of uninjured arteries in hypertensive rats were found to be markedly upregulated. The endothelial cells of the injured arteries with many neutrophil and monocyte adhesion similarly showed marked expression of ICAM-1, and were strongly positive for IL-1α, IL-6, IL-8, and TNF-α. The medial smooth muscle cells positive for IL-1α, IL-6, IL-8 or TNF-α could not be detected in both control and hypertensive rat arteries.
These results suggest that the hypertension activates endothelial cells to increase the adhesion molecule and cytokine production, and induces the neutrophil adhesion and migration in the arterial wall resulting in the hypertensive arterial lesions. Expression of cytokines such as IL-1α, IL-6, IL-8 and TNF-α in medial muscle cells of rat arteries was not induced by hypertension.
