Inhibitory effect of recombinant iNOS gene expression on vasomotor function of canine basilar artery.
The present study was designed to determine the effect of recombinant inducible nitric oxide (NO) synthase (iNOS) gene expression on vasomotor function in cerebral arteries. Isolated canine basilar arteries were exposed ex vivo (30 min at 37 degrees C) to an adenoviral vector [10(7), 10(8), or 10(9) plaque-forming units (pfu)/ml] encoding either the iNOS gene or the beta-galactosidase reporter gene. Twenty-four hours after transduction, Western blot analysis demonstrated expression of iNOS protein only in iNOS (10(9) pfu/ml)-transduced arteries. Immunohistochemical analysis localized iNOS expression predominantly in adventitia. Vascular reactivity of isolated basilar arteries was studied by isometric force recording. Concentration-response curves to UTP (10(-9)-10(-3) M) and diethylaminodiazen-1-ium-1,2-dioate (10(-10)-10(-5) M) were significantly shifted to the right in iNOS gene (10(9) pfu/ml)-transduced rings compared with control and beta-galactosidase-transduced rings (P < 0.05, n = 5-6). Endothelium-dependent relaxation to bradykinin was significantly attenuated in iNOS-transduced rings (P < 0.001, n = 8). The basal level of cGMP and superoxide anion (O(2)(-).) production were elevated in iNOS-transduced rings (P < 0.05, n = 7 for cGMP; P < 0.01, n = 6-9 for O(2)(-). production). Our results suggest that expression of recombinant iNOS in cerebral arteries reduces vasomotor reactivity to both vasoconstrictor and vasodilator agonists. Attenuation of contractions is most likely due to functional antagonism between UTP and cGMP. Reduction of endothelium-dependent relaxation to bradykinin appears to be mediated in part by reduced reactivity of smooth muscle cells to NO.
Eguchi
Daihiko
D
Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota 55905, USA.
D'Uscio
Livius V
LV
Wambi
Chris
C
Weiler
Deborah
D
Kovesdi
Imre
I
O'Brien
Timothy
T
Katusic
Zvonimir S
ZS
D000818:Animals; D001488:Basilar Artery / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D001920:Bradykinin / Q000494:pharmacology; D006152:Cyclic GMP / Q000378:metabolism; D004285:Dogs; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression / Q000502:physiology*; D018014:Gene Transfer Techniques; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000096:biosynthesis* / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D014544:Uridine Triphosphate / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology; D014666:Vasomotor System / Q000187:drug effects / Q000378:metabolism*
D020030:Nitric Oxide Donors; D011994:Recombinant Proteins; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D006152:Cyclic GMP; D001920:Bradykinin; D014544:Uridine Triphosphate