title: RGDN peptide interaction with endothelial alpha5beta1 integrin causes sustained endothelin-dependent vasoconstriction of rat skeletal muscle arterioles.
abstract: The ability of an integrin-binding Arg-Gly-Asp-Asn (RGDN)- containing peptide to influence vascular tone by interacting with the alpha5beta1 integrin was studied using rat skeletal muscle arterioles. After blockade of beta3 integrin function, isolated arterioles with spontaneous tone showed concentration-dependent vasoconstrictions to topical application of GRGDNP, a peptide that shows a greater ability to interact with alpha5beta1 than with alphavbeta3. The constriction to GRGDNP (2.1 mM) was inhibited by blocking alpha5 integrin function, and was intensified by blocking beta3 integrin function. In contrast, GRGDSP, a peptide that interacts better with alphavbeta3, was unable to induce sustained constrictions. Removal of the endothelium abolished the vasoconstriction in response to GRGDNP, suggesting that the response was due to release of an endothelium-dependent factor. Indeed, blockade of ETA endothelin receptors with BQ-610 (1 microM), similar to removal of the endothelium and alpha5 integrin blockade, inhibited the vasoconstriction. These data indicate that interaction of RGD peptides, and in particular the RGDN sequence with endothelial cell alpha5beta1, causes endothelin-mediated arteriolar vasoconstriction. These results indicate that integrins are novel signaling receptors within the vascular wall that affect vasomotor tone, and may play an important role in vascular control.
authors.affiliation: Microcirculation Research Institute and Department of Medical Physiology, Texas A&M University Health Science Center, Texas A&M University, College Station, Texas 77843-1114, USA. gam@tamu.edu
authors.forename: J E
authors.initials: JE
authors.lastname: Mogford
authors.forename: G E
authors.initials: GE
authors.lastname: Davis
authors.forename: G A
authors.initials: GA
authors.lastname: Meininger
mesh_terms: D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology; D015703:Antigens, CD / Q000276:immunology; D001160:Arterioles / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D065128:Endothelin Receptor Antagonists; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D005353:Fibronectins / Q000494:pharmacology; D066298:In Vitro Techniques; D039482:Integrin alpha5; D039661:Integrin beta3; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000187:drug effects / Q000502:physiology; D009842:Oligopeptides / Q000494:pharmacology*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D010980:Platelet Membrane Glycoproteins / Q000276:immunology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044022:Receptor, Endothelin A; D017469:Receptors, Fibronectin / Q000502:physiology*; D019030:Receptors, Vitronectin / Q000502:physiology; D013997:Time Factors; D014661:Vasoconstriction / Q000502:physiology
chemical_list: D019138:Antibodies, Blocking; D015703:Antigens, CD; D065128:Endothelin Receptor Antagonists; D005353:Fibronectins; D039482:Integrin alpha5; D039661:Integrin beta3; D009842:Oligopeptides; D010975:Platelet Aggregation Inhibitors; D010980:Platelet Membrane Glycoproteins; C109085:RGDN peptide; D044022:Receptor, Endothelin A; D017469:Receptors, Fibronectin; D019030:Receptors, Vitronectin; C087220:BQ 610; C046617:arginyl-glycyl-aspartyl-serine