Zukowska-Grojec Z, Marks E S, Haass M
Department of Physiology and Biophysics, Georgetown University, Washington, DC 20007.
Am J Physiol. 1987 Nov;253(5 Pt 2):H1234-9. doi: 10.1152/ajpheart.1987.253.5.H1234.
Neuropeptide Y (NPY) is contained in and coreleased with norepinephrine (NE) from sympathetic nerves innervating vascular and cardiac tissues. The effects of NPY infusion on systemic hemodynamics and cardiac performance were compared with those of NE in conscious and pentobarbital sodium-anesthetized rats. A 10-min infusion of NPY (2 nmol.kg-1.min-1) decreased cardiac index (CI) 20% and stroke volume index (SVI) 9% with increases of 20% in mean arterial pressure (MAP) and 48% in total peripheral resistance (TPR). Conversely, NE (1.0 microgram.kg-1.min-1) increased SVI 14%, MAP 29%, and TRP 26%, with no change in CI. Heart rates decreased similarly (approximately 60 beats/min) but only NE-induced bradycardia was reversible by methylatropine nitrate. In anesthetized rats NPY (0.1 nmol.kg-1.min-1) increased left ventricular end-diastolic pressure (LVEDP) 20 +/- 10 mmHg (means +/- SD, n = 7) and decreased dP/dt by 8 +/- 6%. NE (0.07 microgram.kg-1.min-1) produced an equivalent pressor response, however, dP/dt rose 22 +/- 10% whereas LVEDP increased significantly less than with NPY. Thus NPY is a potent vasoconstrictor exerting similar effects to NE on MAP and TPR but, unlike NE, possesses negative inotropic and chronotropic activity.
神经肽Y（NPY）存在于支配血管和心脏组织的交感神经中，并与去甲肾上腺素（NE）共同释放。在清醒和戊巴比妥钠麻醉的大鼠中，比较了输注NPY对全身血流动力学和心脏功能的影响与NE的影响。输注10分钟的NPY（2 nmol·kg⁻¹·min⁻¹）使心脏指数（CI）降低20%，每搏量指数（SVI）降低9%，平均动脉压（MAP）升高20%，总外周阻力（TPR）升高48%。相反，NE（1.0 μg·kg⁻¹·min⁻¹）使SVI升高14%，MAP升高29%，TRP升高26%，CI无变化。心率同样降低（约60次/分钟），但只有NE引起的心动过缓可被硝酸甲基阿托品逆转。在麻醉大鼠中，NPY（0.1 nmol·kg⁻¹·min⁻¹）使左心室舒张末期压力（LVEDP）升高20±10 mmHg（平均值±标准差，n = 7），dP/dt降低8±6%。NE（0.07 μg·kg⁻¹·min⁻¹）产生了等效的升压反应，然而，dP/dt升高22±10%，而LVEDP的升高明显低于NPY。因此，NPY是一种强效血管收缩剂，对MAP和TPR的作用与NE相似，但与NE不同的是，它具有负性肌力和变时活性。
