Balloon angioplasty enhances the expression of angiotensin II AT1 receptors in neointima of rat aorta.
AUTOR(ES)
Viswanathan, M
RESUMO
Angiotensin II is a vasoactive peptide and may act as a growth factor in vascular smooth muscle cells. Experimental injury of the rat aorta causes rapid migration of medial smooth muscle cells and their proliferation resulting in the formation of neointima. We have examined, using quantitative autoradiography, the expression of angiotensin II receptor subtypes AT1 and AT2, and angiotensin-converting enzyme, in the neointima formed in the rat thoracic aorta 15 d after balloon-catheter injury. In contrast to the normal aortic wall, which contained both AT1 and AT2 receptors (80% and 20%, respectively), neointimal cells expressed almost exclusively angiotensin II AT1 receptors. The apparent number of these receptors was fourfold higher in the neointima compared to that in the normal aortic wall. The affinities of the neointimal receptors to angiotensin II or to the AT1 receptor antagonist, losartan, were not different from those in the normal aortic wall. Angiotensin-converting enzyme binding in the neointima was not different from that in the media of the uninjured aorta. Our data suggest that angiotensin II AT1 receptors may have a significant role in injury-induced vascular smooth muscle proliferation and migration.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=443227Documentos Relacionados
- Percutaneous transluminal balloon angioplasty in restenosis of coarctation of the aorta.
- Angiotensin II AT1 blockade reduces the lipopolysaccharide-induced innate immune response in rat spleen
- Differential distribution of AT1 and AT2 angiotensin II receptor subtypes in the rat brain during development.
- Role of AT1 receptors in the resetting of the baroreflex control of heart rate by angiotensin II in the rabbit.
- Hypercalcemia stimulates expression of intrarenal phospholipase A2 and prostaglandin H synthase-2 in rats. Role of angiotensin II AT1 receptors.