PMID: 2506768Sep 1, 1989Paper

Coronary constriction due to neuropeptide Y: alleviation with cyclooxygenase blockers

The American Journal of Physiology
S E Martin, R E Patterson

Abstract

Intra-arterial administration of neuropeptide Y (NPY), a peptide endogenous to sympathetic nerves, increases coronary vascular resistance by 30-40%. To test whether blockade of prostaglandin synthesis altered the severity of the NPY-induced coronary vasoconstriction, dogs (n = 25) were anesthetized and instrumented to record hemodynamic parameters. In control animals (n = 11) paired infusions of NPY (42 nmol/3 min) were given at 0 and 120 min. NPY produced similar increases in coronary resistance by 10 min, 31 +/- 7% (mean +/- SD) with the first dose vs. 32 +/- 12% with the second dose. The increases in resistance were due to an initial decrease in coronary flow (10 +/- 6%) followed by a prolonged increase in aortic pressure (15-20% over 20 min). Each infusion of NPY decreased heart rate (-10 +/- 7%) but did not alter left ventricular dP/dt. The effects of NPY lasted 40-60 min. In a separate group, a cyclooxygenase inhibitor (COI), indomethacin (n = 6) or ibuprofen (n = 8), was given 1 h before the second dose of NPY. The increases in coronary resistance were blunted significantly after cyclooxygenase blockade from a predrug value of 36 +/- 13 to 19 +/- 12%. In these treated animals, the decrease (-12 +/- 6%) in coronary blood ...Continue Reading

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