Gene transfer of endothelial nitric oxide synthase but not Cu/Zn superoxide dismutase restores nitric oxide availability in the SHRSP.
OBJECTIVE
Previous studies from our group have shown a deficit in nitric oxide (NO) bioavailability and an excess production of the superoxide anion (O(2)(-)) in the stroke prone spontaneously hypertensive rat (SHRSP) compared to the normotensive Wistar Kyoto (WKY) strain. This present study has investigated whether adenoviral-mediated gene transfer of human eNOS or Cu/ZnSOD can alter the NO/O(2)(-) balance, thereby improving endothelial function.


METHODS
A recombinant adenovirus, Ad/Hu/eNOS, containing the human eNOS cDNA fragment was generated by homologous recombination in 293 cells. Ad/Hu/eNOS or Ad/Cu/ZnSOD was delivered into SHRSP carotid arteries in vivo, using a titre of 2x10(9)-2x10(10) plaque forming units (pfu)/ml, and the effect on gene expression was observed 24 h later.


RESULTS
Western blotting confirmed increased enzyme levels of eNOS and Cu/ZnSOD in the viral-infused vessels. Ex vivo, the pressor response to phenylephrine (PE) in the presence of L-NAME was increased in the eNOS-infused arteries relative to the contralateral controls, indicating restoration of basal NO availability to that observed in untreated control WKY rats. Infusion of the SOD virus produced a statistically insignificant increase in NO bioavailability.


CONCLUSIONS
Our results support our previous findings obtained using a bovine eNOS recombinant adenovirus, that recombinant adenoviral gene transfer of human eNOS has a significant effect on NO bioavailability. In contrast, AdCu/ZnSOD gene transfer does not elicit an effect in our model. These results indicate that short-term overexpression of a recombinant eNOS, but not Cu/ZnSOD gene, in carotid arteries of the SHRSP is an effective means of locally increasing NO bioavailability to improve endothelial function.
Alexander
M Y
MY
Department of Medicine and Therapeutics, University of Glasgow, Western Infirmary, Church St., G11 6NT, Scotland, Glasgow, UK. yalexander@clinmed.gla.ac.uk
Brosnan
M J
MJ
Hamilton
C A
CA
Fennell
J P
JP
Beattie
E C
EC
Jardine
E
E
Heistad
D D
DD
Dominiczak
A F
AF
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D001011:Aorta; D001682:Biological Availability; D015153:Blotting, Western; D002339:Carotid Arteries; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000008:administration & dosage; D006801:Humans; D006973:Hypertension / Q000201:enzymology* / Q000628:therapy; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000037:antagonists & inhibitors / Q000235:genetics*; D052250:Nitric Oxide Synthase Type III; D010656:Phenylephrine / Q000494:pharmacology; D010957:Plasmids; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013482:Superoxide Dismutase / Q000032:analysis / Q000235:genetics*; D014162:Transfection / Q000379:methods*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D004791:Enzyme Inhibitors; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D009569:Nitric Oxide; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D013482:Superoxide Dismutase; D019331:NG-Nitroarginine Methyl Ester