IMPACT OF CORONARY RISK-FACTORS ON CONTRIBUTION OF NITRIC-OXIDE AND ADENOSINE TO METABOLIC CORONARY VASODILATION IN HUMANS

Citation
T. Minamino et al., IMPACT OF CORONARY RISK-FACTORS ON CONTRIBUTION OF NITRIC-OXIDE AND ADENOSINE TO METABOLIC CORONARY VASODILATION IN HUMANS, Journal of the American College of Cardiology, 31(6), 1998, pp. 1274-1279
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiac & Cardiovascular System
ISSN journal
0735-1097
Volume
31
Issue
6
Year of publication
1998
Pages
1274 - 1279
Database
ISI
SICI code
0735-1097(1998)31:6<1274:IOCROC>2.0.ZU;2-0
Abstract
Objectives. The contribution of nitric oxide (NO) and adenosine to the increase in coronary blood flow (CBF) induced by cardiac pacing was i nvestigated in 28 subjects with angiographically normal coronary arter ies with and without one or more risk factors for atherosclerosis, Bac kground. NO and adenosine are important in the regulation of coronary circulation, and the inhibition of NO synthesis increases adenosine pr oduction during cardiac pacing in experimental models. Methods. Corona ry artery diameters and CBF were assessed by quantitative coronary art eriography and Doppler flow velocity measurement. Plasma levels of nit rites and nitrates (NOx) (stable end products of NO), adenosine and la ctate mere measured, and blood gas analysis,vas performed. Results. Th e extent of CBF response to cardiac pacing did not differ between the 14 subjects with and the 8 subjects without risk factors for atheroscl erosis, NOx (12.0 +/- 0.9 vs. 14.9 +/- 1.1 mu mol/liter [mean +/- SD], p < 0.05), but not adenosine (50.8 +/- 7.2 vs. 50.8 +/- 6.5 nmol/lite r), levels in coronary sinus blood increased in the subjects without r isk factors. In contrast, adenosine (58.9 +/- 7.5 vs. 77.4 +- 9.8 nmol /liter, p < 0.05), but not NOx (11.1 +/- 1.1 vs. 12.2 +/- 1.1 mu mol/l iter), levels increased in subjects with risk factors. Aminophylline, an antagonist of adenosine receptors, blunted CBF response to cardiac pacing in six subjects with risk factors. The number of risk factors s howed a negative correlation (p < 0.05) with NOx production and a posi tive correlation (p < 0.05) with adenosine production during cardiac p acing, respectively, Conclusions, NO and adenosine are increased durin g metabolic coronary vasodilation induced by cardiac pacing. Adenosine production may be a compensatory mechanism when NO production is redu ced.