title: Enhanced endothelium-dependent relaxations after gene transfer of recombinant endothelial nitric oxide synthase to rabbit carotid arteries.
abstract: We tested the effects of overexpression of the endothelial nitric oxide synthase (eNOS) gene in the normal arterial wall by adenoviral-mediated gene transfer. Rabbit carotid arteries were surgically isolated and exposed to adenoviral vectors encoding eNOS (AdeNOS) or beta-galactosidase (Ad betaGal) on the contralateral side. Vector solutions at a concentration of 1 x 10(10) plaque forming units/mL were instilled for 20 minutes before restoration of flow. Arteries were harvested 4 days later for immunostaining, measurement of cGMP, and vasomotor studies. Endothelium-specific gene transfer was confirmed by staining for beta-galactosidase in the Ad betaGal arteries. Immunostaining of en face endothelial cell imprints from AdeNOS-transduced arteries with a monoclonal antibody to eNOS showed increased immunoreactivity. Basal cGMP levels were significantly greater in the AdeNOS-transduced arteries (18.4+/-4.6 versus 4.2+/-0.5 pmol/mg protein; P<.05). Contractions to phenylephrine were significantly reduced in the AdeNOS-transduced arteries (area under curve, 106+/-5 versus 119+/-7; P<.05), but in the presence of the eNOS inhibitor, N(G)-monomethyl-L-arginine (L-NMMA, 3 x 10(-4) mol/L), there was no difference between the two (area under curve, 148+/-5 versus 153+/-6; P=NS). Relaxations to acetylcholine obtained during submaximal contractions to phenylephrine were significantly enhanced in the AdeNOS-transduced arteries (EC50, 7.45+/-0.05 versus 7.23+/-0.03; P<.05). We conclude that overexpression of eNOS in the endothelium results in diminished contractile responses, as well as enhanced endothelium-dependent relaxations. These findings imply a possible role for vascular eNOS gene transfer in the treatment of vasospasm and endothelial dysfunction.
authors.affiliation: Division of Cardiovascular Disease, Mayo Clinic and Foundation, Rochester, Minn. 55905, USA.
authors.forename: I J
authors.initials: IJ
authors.lastname: Kullo
authors.forename: G
authors.initials: G
authors.lastname: Mozes
authors.forename: R S
authors.initials: RS
authors.lastname: Schwartz
authors.forename: P
authors.initials: P
authors.lastname: Gloviczki
authors.forename: M
authors.initials: M
authors.lastname: Tsutsui
authors.forename: Z S
authors.initials: ZS
authors.lastname: Katusic
authors.forename: T
authors.initials: T
authors.lastname: O'Brien
mesh_terms: D000818:Animals; D002339:Carotid Arteries / Q000502:physiology*; D006152:Cyclic GMP / Q000378:metabolism; D004730:Endothelium, Vascular / Q000201:enzymology* / Q000502:physiology*; D018014:Gene Transfer Techniques; D008297:Male; D019001:Nitric Oxide Synthase / Q000235:genetics*; D010656:Phenylephrine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D011817:Rabbits; D011994:Recombinant Proteins; D014661:Vasoconstriction; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000502:physiology*
chemical_list: D011994:Recombinant Proteins; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D011189:Potassium Chloride; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP