Atriopeptin II lowers cardiac output in conscious sheep.
Atriopeptin II lowers cardiac output in conscious sheep.
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Atriopeptin II 会降低清醒羊的心输出量。
DOI：
10.1152/ajpregu.1985.249.6.r776
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Chimoskey,JE
中科院分区：
文献类型：
--
作者：
Breuhaus,BA;Saneii,HH;Brandt,MA;Chimoskey,JE
心房钠尿肽可引起尿钠排钠、排钾、利尿和低血压。它们在体外松弛血管平滑肌，并在体内扩张肾血管。因此，我们测试了它们通过降低总外周阻力而产生低血压的假设。这些研究是在清醒的、长期佩戴仪器的羊身上进行的，这些羊静静地站在笼子里。心房肽 II (AP II) 以 0.1 nmol X kg-1 X min-1 输注至右心房 30 分钟。 Atriopeptin II 通过降低心输出量（18%，P 小于 0.05）、每搏输出量（28%，P 小于 0.05）和右心房压力（2.3 mmHg，P 小于 0.05）来降低动脉压（9%，P 小于 0.05）。心率和总外周阻力增加（分别为 16% 和 13%，P 小于 0.05）。 AP II 输注期间用凸轮磺酸三甲芬部分阻断神经节可防止心率和总外周阻力的增加。右心房压力、每搏输出量和心输出量的变化持续存在，动脉压进一步下降（27%，P小于0.05）。这些血流动力学数据与直接 AP II 诱导的静脉平滑肌松弛、静脉回流、右心房压力、每搏输出量、心输出量和动脉压降低一致，随后交感神经系统反射性激活，增加心率和总外周阻力。因为单独部分神经节阻滞和单独 AP II 会引起类似的右心房压力降低（分别为 2.1 和 2.3 mmHg），但 AP II 会导致每搏输出量下降更大（28% vs. 13%），因此 AP II 也可能会引起冠状血管收缩。
Atrial natriuretic peptides cause natriuresis, kaliuresis, diuresis, and hypotension. They relax vascular smooth muscle in vitro, and they dilate renal vessels in vivo. Hence, we tested the hypothesis that they produce hypotension by lowering total peripheral resistance. The studies were performed in conscious chronically instrumented sheep standing quietly in their cages. Atriopeptin II (AP II) was infused into the right atrium for 30 min at 0.1 nmol X kg-1 X min-1. Atriopeptin II lowers arterial pressure (9%, P less than 0.05) by lowering cardiac output (18%, P less than 0.05), stroke volume (28%, P less than 0.05), and right atrial pressure (2.3 mmHg, P less than 0.05). Heart rate and total peripheral resistance increase (16 and 13%, respectively, P less than 0.05). Partial ganglionic blockade with trimethaphan camsylate during AP II infusion prevents the increases in heart rate and total peripheral resistance. The changes in right atrial pressure, stroke volume, and cardiac output persist, and arterial pressure falls further (27%, P less than 0.05). These hemodynamic data are consistent with direct AP II-induced relaxation of venous smooth muscle with reduction of venous return, right atrial pressure, stroke volume, cardiac output, and arterial pressure, followed by reflex activation of the sympathetic nervous system to increase heart rate and total peripheral resistance. Because partial ganglionic blockade alone and AP II alone cause similar reductions in right atrial pressure (2.1 and 2.3 mmHg, respectively) but AP II causes a greater fall in stroke volume (28 vs. 13%), it is possible that AP II also causes coronary vasoconstriction.