Neuropeptide-Y. A peptide found in human coronary arteries constricts primarily small coronary arteries to produce myocardial ischemia in dogs.

Abstract

(LVEF), measured by radionuclide angiography, decreased from 0.52±0.08 to 0.42±0.12 U (n = 5, P < 0.01) during NPY. NPY-induced vasoconstriction was also associated with ST-T wave changes on the electrocardiogram (ECG) in eight of nine other animals (group V). In another group of six dogs (group IV), the change in small vessel resistance accounted for 94% of the increase in total resistance, so that the primary vasoconstrictor effect of NPY was exerted on small coronary arteries. Thus, NPY, a peptide found in human coronary arteries, caused constriction of primarily small coronary arteries that was severe enough to produce myocardial ischemia as determined by ECG ST-T wave changes, and decreases in intramyocardial pH and LVEF in dogs.

Neuropeptide Y (NPY) and NPY receptors in the cardiovascular system: implication in the regulation of intracellular calciumThis paper is one of a selection of papers published in this Special Issue, entitled Young Investigators' Forum.

“…Our results in hVSMCs are in accordance with most of the previously reported work in the literature using several types of VSM from various species (Grundemar et al 1992;Lundberg and Modin 1995;Shigeri et al 1991). The sustained increase of cytosolic free Ca 2+ in VSM may explain the observed reduction in coronary blood flow and increase in vascular resistance of various species including humans (Allen et al 1983;FrancoCereceda et al 1985;Balasubramaniam et al 1988;Clarke et al 1987;Maturi et al 1989). On the other hand, the sustained increase in resting nuclear free Ca 2+ could contribute to the mitogenic effect of NPY as is the case for VSM proliferation in atherosclerosis and angiogenesis as well as endothelial cell proliferation following angioplasty (Zukowska-Grojec et al 1998a, 1998bJacques et al 2003aJacques et al , 2006b.…”

Chronic type II diabetes mellitus leads to changes in neuropeptide Y receptor expression and distribution in human myocardial tissue

“…Recently, neuropeptide Y itself has been shown to be regulated by leptin in the hypothalamus and peripheral autonomic nervous system. In the cardiovascular system neuropeptide Y is co-localized with the classic sympathetic neurotransmitter noradrenaline, present in sympathetic nerves innervating coronary arteries (Maturi et al, 1989), cardiomyocytes, and endothelium (Jonsson-Rylander et al, 2003). It has been shown to act by multiple G coupled receptors (Y 1 –Y 5 ) on vascular endothelial cells (Uddman et al, 2002), vascular smooth muscle (VSMC), cardiomyocytes (Nicholl et al, 2002), immune and fat cells.…”

Neuropeptide Y induced increase of cytosolic and nuclear Ca2+in heart and vascular smooth muscle cells

“…A variety of actions have been attributed to NPY in the control of cardiovascular functions, which include a role as a potent constrictor of both arteries and veins (Edvinsson et al 1987;Zukowska-Grojec et al 1987), a stimulator of myocyte hypertrophy (Millar et al 1994;Goldberg et al 1998), and a mitogen for vascular smooth muscle cells (Zukowska-Grojec et al 1998b). In the heart, the in vivo infusion of NPY reduces coronary blood flow and increases vascular resistance in various species including humans (Allen et al 1983;Franco-Cereceda et al 1985;Balasubramaniam et al 1988;Clarke et al 1987;Maturi et al 1989). Moreover, the documented actions of NPY on cardiac contraction are somewhat divergent, depending on the species and tissue used.…”