Boucher M, Chassaing C, Chapuy E, Lorente P
INSERM U.195, Faculty of Medicine, Clermont-Ferrand, France.
Regul Pept. 1994 Dec 15;54(2-3):409-15. doi: 10.1016/0167-0115(94)90538-x.
The chronotropic cardiac effects of neuropeptide Y (NPY) were studied in the conscious dog with chronic atrioventricular block. NPY (0.2-5 micrograms/kg i.v.) produced no effect on atrial cycle length (ACL), and increased ventricular cycle length (VCL) and mean arterial blood pressure (MBP). After atropine, NPY produced no effect on ACL and increased MBP. At 0.2 microgram/kg, it shortened VCL, whereas at 1 and 5 micrograms/kg, it lengthened this parameter. After pindolol, NPY produced no effect on ACL, shortened VCL and increased MBP. These results indicate that in the conscious dog, NPY (0.2-5 microgram/kg i.v.) does not exert any chronotropic effect on the sinoatrial node, most likely because of competition between opposite chronotropic effects and/or absence of specific NPY receptors in the sinoatrial node. They also suggest that the ventricular bradycardic effects produced by NPY result mainly from a reflex withdrawal of beta-adrenergic tone and that its ventricular tachycardic effects result from a direct action of NPY on specific receptors located in the His bundle.
在患有慢性房室传导阻滞的清醒犬中研究了神经肽Y（NPY）对心率的影响。静脉注射NPY（0.2 - 5微克/千克）对心房周期长度（ACL）无影响，但增加了心室周期长度（VCL）和平均动脉血压（MBP）。阿托品给药后，NPY对ACL无影响，但增加了MBP。在0.2微克/千克时，它缩短了VCL，而在1和5微克/千克时，它延长了该参数。吲哚洛尔给药后，NPY对ACL无影响，缩短了VCL并增加了MBP。这些结果表明，在清醒犬中，静脉注射NPY（0.2 - 5微克/千克）对窦房结没有任何变时作用，最可能的原因是相反变时作用之间的竞争和/或窦房结中缺乏特异性NPY受体。它们还表明，NPY产生的心室心动过缓效应主要源于β-肾上腺素能张力的反射性减弱，而其心室心动过速效应则源于NPY对希氏束中特定受体的直接作用。
