Up regulation of AT4 receptor levels in carotid arteries following balloon injury
| Autor: | Paul A. Fennessy, John A. Bingley, Frederick A.O. Mendelsohn, Eleanor F. Clune, Anthony L. Albiston, Siew Yeen Chai, Ingrid Moeller |
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| Rok vydání: | 1999 |
| Předmět: |
Male
Neointima medicine.medical_specialty Angiotensin receptor Vascular smooth muscle Carotid Artery Common Physiology Clinical Biochemistry Angiotensin III In Vitro Techniques Biology Biochemistry Cellular and Molecular Neuroscience Endocrinology Internal medicine medicine Animals Angioplasty Balloon Coronary Receptors Angiotensin Angiotensin II receptor type 1 Angiotensin II Balloon catheter Up-Regulation medicine.anatomical_structure Vasa vasorum Carotid Artery External cardiovascular system Rabbits Carotid Artery Injuries |
| Zdroj: | Regulatory Peptides. 83:25-30 |
| ISSN: | 0167-0115 |
| DOI: | 10.1016/s0167-0115(99)00047-6 |
| Popis: | Angiotensin IV, (V-Y-I-H-P-F), binds to AT4 receptors in blood vessels to induce vasodilatation and proliferation of cultured bovine endothelial cells. This latter effect may be important not only in developing tissues but also in injured vessels undergoing remodelling. In the present study, using normal rabbit carotid arteries, we detected AT4 receptors in vascular smooth muscle cells and in the vasa vasorum of the adventitia. Very low receptor levels were observed in the endothelial cells. In keeping with the described binding specificity of AT4 receptors, unlabelled angiotensin IV competed for [125I]angiotensin IV binding in the arteries, with an IC50 of 1.4 nM, whereas angiotensin II and angiotensin III were weaker competitors. Within the first week following endothelial denudation of the carotid artery by balloon catheter, AT4 receptor binding in the media increased to approximately 150% of control tissue. AT4 receptor binding further increased in the media, large neointima and re-endothelialized cell layer to 223% at 20 weeks after injury. In view of the known trophic effects of angiotensin IV, the elevated expression of AT4 receptors, in both the neointima and media of arteries, following balloon injury to the endothelium, suggests a role for the peptide in the adaptive response and remodelling of the vascular wall following damage. |
| Databáze: | OpenAIRE |
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