Nitric Oxide

Table of Contents

Hypertension. 1997;30:307-313
doi: 10.1161/01.HYP.30.3.307

(Hypertension. 1997;30:307.)
© 1997 American Heart Association, Inc.

Articles

Prolonged Reduction of High Blood Pressure With Human Nitric Oxide Synthase Gene Delivery

Kuei-Fu Lin; Lee Chao; Julie Chao

From the Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston.
Correspondence to Julie Chao, PhD, or Lee Chao, PhD, Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 171 Ashley Ave, Charleston, SC 29425.

Abstract Endothelium-derived nitric oxide (NO) in peripheral vessels has been shown to modulate vascular resistance and blood pressure. We explored the effect of a continuous supply of human endothelial NO synthase (eNOS) on the blood pressure of spontaneously hypertensive rats (SHR) by somatic gene delivery. A DNA construct containing the human eNOS gene fused to the cytomegalovirus promoter/enhancer was injected into SHR through the tail vein. A single injection of the naked eNOS plasmid DNA caused a significant reduction of systemic blood pressure for 5 to 6 weeks in SHR, and the effect continued for up to 10 to 12 weeks after a second injection. The differences were significant from 2 to 12 weeks postinjections (n=6, P<.01). In a separate experiment, L-arginine, the substrate of eNOS, was supplied in drinking water at a concentration of 7.5 g/L for 11 weeks after eNOS gene delivery. A maximal blood pressure reduction of 21 mm Hg in SHR was observed with eNOS DNA compared with that of control SHR injected with vector DNA (181.9±1.46 versus 202.7±2.79 mm Hg, mean±SEM, n=6, P<.01). Human eNOS gene delivery induces significant increases in urinary and aortic cGMP levels and urinary and serum nitrite/nitrate content (P<.05), while no significant differences in body weight, heart rate, water intake, food consumption, or urine excretion were observed. These results indicate that somatic delivery of the human eNOS gene induces a prolonged reduction of high blood pressure and raises the potential of using eNOS gene therapy for hypertension and cardiovascular diseases.

Key Words: nitric oxide synthase • inbred SHR • somatic gene therapy • blood pressure • hypertension