title: Viral-mediated gene delivery of constitutively activated G alpha s alters vasoreactivity.
abstract: 1. Decline in beta-adrenoceptor (beta-AR)-mediated function occurs with increasing age, as well as in multiple disease conditions. The mechanisms responsible for this decline include alterations in beta-AR itself, beta-AR coupling proteins, such as G-proteins, or other beta-AR-linked proteins, such as G-protein receptor kinases and/or phosphatases. 2. The present study examines the physiological effects of in vitro transfer of constitutively activated G alpha s (G alpha s-Q227L) to both cultured vascular smooth muscle cells (VSMC) and whole aortic tissue of 6-month-old (adult) animals via a replication-deficient Herpes simplex virus (HSV) vector. These studies were conducted to provide a model for future examination of the role of G alpha s in the age-related decline in beta-AR-mediated vasorelaxation. 3. Gene transfer was confirmed by western blotting for specific proteins. Aortic tissue infected with HSV-G alpha s-Q227L had reduced phenylephrine-induced contraction and enhanced isoproterenol-stimulated vasorelaxation. Infection of cultured VSMC with HSV-G alpha s-Q227L increased both basal- and isoproterenol-stimulated cAMP accumulation, whereas forskolin-stimulated cAMP production was unchanged. 4. These results implicate G alpha s as a target for further investigation in age-related changes in vascular reactivity and support the use of viral-mediated gene transfer as an effective tool to study adrenergic signal transduction and physiology in vascular tissue.
authors.affiliation: Portland VA Medical Center, Research Service, Oregon, USA.
authors.forename: W E
authors.initials: WE
authors.lastname: Schutzer
authors.forename: V J
authors.initials: VJ
authors.lastname: Watts
authors.forename: J
authors.initials: J
authors.lastname: Chapman
authors.forename: M G
authors.initials: MG
authors.lastname: Cumbay
authors.forename: K A
authors.initials: KA
authors.lastname: Neve
authors.forename: R L
authors.initials: RL
authors.lastname: Neve
authors.forename: S L
authors.initials: SL
authors.lastname: Mader
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000235:genetics / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D018139:Simplexvirus / Q000235:genetics; D014664:Vasodilation / Q000235:genetics / Q000502:physiology*
chemical_list: D000242:Cyclic AMP; D019204:GTP-Binding Proteins