Westfall T C, Yang C L, Curfman-Falvey M
Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, Missouri, 63104, USA.
J Cardiovasc Pharmacol. 1995 Nov;26(5):682-7. doi: 10.1097/00005344-199511000-00002.
Neuropeptide Y (NPY) and ATP are considered cotransmitters with norepinephrine (NE) in sympathetic neurons innervating some blood vessels, including those of the mesentery. A prominent action of NPY is to potentiate the postjunctional contractile effect of NE as well as that of other vasoactive agents. We wished to investigate whether NPY also potentiates the contractile effect of ATP and, if so, to determine which receptor subtype mediates such an effect. The effect of NPY, the NPY-Y1-selective agent Leu31Pro34 NPY, and the NPY-Y2-selective fragment NPY 14-36 on the increase in perfusion pressure produced by ATP was examined in rat perfused mesenteric arterial bed. Results demonstrated that both NPY and Leu31Pro34 NPY but not NPY 14-36 potentiated the increase in perfusion pressure produced by ATP. These results suggest that NPY acts on Y1 receptors to enhance the postjunctional response of ATP. The putative NPY antagonist PYX2, but not the putative antagonists benextramine or PYX1, attenuated the effect of NPY, indicating that PYX2 acts as an NPY antagonist in this system. A major action of NPY is to enhance the postjunctional response of both cotransmitters, ATP and NE at the vascular sympathetic neuroeffector junction in the mesenteric arterial bed, and this may be mediated by NPY-Y1 receptors.
神经肽Y（NPY）和ATP被认为是与去甲肾上腺素（NE）共同存在于支配包括肠系膜血管在内的一些血管的交感神经元中的神经递质。NPY的一个显著作用是增强NE以及其他血管活性物质的节后收缩效应。我们希望研究NPY是否也能增强ATP的收缩效应，如果是，确定是哪种受体亚型介导这种效应。在大鼠灌注肠系膜动脉床中，研究了NPY、NPY-Y1选择性试剂Leu31Pro34 NPY和NPY-Y2选择性片段NPY 14-36对ATP引起的灌注压升高的影响。结果表明，NPY和Leu31Pro34 NPY均能增强ATP引起的灌注压升高，而NPY 14-36则不能。这些结果表明，NPY作用于Y1受体以增强ATP的节后反应。推测的NPY拮抗剂PYX2，但不是推测的拮抗剂苄奈明或PYX1，减弱了NPY的作用，表明PYX2在该系统中作为NPY拮抗剂起作用。NPY的一个主要作用是增强肠系膜动脉床血管交感神经效应器连接处两种共同递质ATP和NE的节后反应，这可能由NPY-Y1受体介导。
