Oxidative stress attenuates NO-induced modulation of sympathetic neurotransmission in the mesenteric arterial bed of spontaneously hypertensive rats

摘要

sympathetic nerves synthesize and release the neurotransmit-ters norepinephrine, neuropeptide Y (NPY), and adenosine triphosphate (ATP) (30, 34, 37, 57). ATP mediates the rapid phase, norepinephrine the intermediate phase, and NPY the long-lasting phase of sympathetic nerve stimulation-induced vasoconstriction (24, 30, 43, 54). The postjunctional vasocon-strictive effects of norepinephrine, NPY, and ATP on blood vessels are mediated through vascular smooth muscle cti, Yi, and P2x receptors, respectively. In addition, norepinephrine, NPY, and ATP have prejunctional inhibitory actions on sympathetic neurotransmission through a2, Y2, and P2y receptors,respectively, that result in the negative regulation of their own release as well as the release of one another (30, 43, 54, 55).