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Reduced gene expression of vascular endothelial NO synthase and cyclooxygenase-1 in heart failure. Circ Res 1996 Jan;78(1):58-64

Date

01/01/1996

Pubmed ID

8603506

DOI

10.1161/01.res.78.1.58

Scopus ID

2-s2.0-9044242645   229 Citations

Abstract

Endothelium-dependent responses are depressed in coronary and peripheral blood vessels after the onset of pacing-induced heart failure in dogs and heart failure of various etiologies in humans. The present study was designed to examine whether these responses were due to decreases in the expression of endothelial cell NO synthase (ecNOS) and cyclooxygenase-1 (COX-1). After 1 month of left ventricular pacing, 8 mongrel dogs were monitored for heart failure as defined by clinical signs and left ventricular end diastolic pressures > 25 mm Hg. Total RNA and protein were isolated from endothelial cells scraped from the thoracic aorta and analyzed by Northern and Western blotting, respectively. Blots probed with 32P-labeled cDNAs for ecNOS and COX-1 were quantified densitometrically, and results were normalized against GAPDH or von Willebrand factor (vWF). In arbitrary units, the ratios of ecNOS to GAPDH were 2.66 +/- 0.77 (mean +/- SEM, n = 17) and 1.12 +/- 0.37 (n = 6 and the ratios of COX-1 to GAPDH were 1.52 +/- 0.52 and 0.56 +/- 0.15 before and after heart failure, respectively. These represent 56% to 64% (P < .05) reductions in ecNOS and COX-1 gene expression. There was no change in the ratios of either COX-1 or ecNOS to vWF. There was also a marked reduction in ecNOS protein after heart failure, estimated at 70%. A marked reduction in nitrite production, a measure of enzyme activity, from thoracic aortas in response to stimulation by either acetylcholine or bradykinin also occurred. To determine whether ecNOS and COX-1 could be independently regulated, an orally active NO-releasing agent, CAS 936, was given to 7 normal dogs for 7 days, and aortic ecNOS and COX-1 mRNAs were analyzed. The ratio of ecNOS to GAPDH was depressed by 52% (P < .05) in aortas from these dogs, whereas the ratio of COX-1 to GAPDH was unchanged. Similar results were found when data were normalized to vWF. These results suggest that at least two endothelial vasodilator gene products are reduced in heart failure, as opposed to a selective defect in NO synthase gene expression.

Author List

Smith CJ, Sun D, Hoegler C, Roth BS, Zhang X, Zhao G, Xu XB, Kobari Y, Pritchard K Jr, Sessa WC, Hintze TH

Author

Kirkwood A. Pritchard PhD Professor in the Surgery department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Animals
Dogs
Endothelium, Vascular
Gene Expression Regulation
Heart Failure
Nitric Oxide Synthase
Prostaglandin-Endoperoxide Synthases
RNA, Messenger
Sydnones
Vasodilator Agents
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a