Sympathetic and cardiovascular actions of orexins in conscious rats
Sympathetic and cardiovascular actions of orexins in conscious rats
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DOI：
10.1152/ajpregu.1999.277.6.r1780
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发表时间：
1999-12-01
影响因子：
2.8
通讯作者：
Kannan, H
中科院分区：
文献类型：
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作者：
Shirasaka, T;Nakazato, M;Kannan, H
新的下丘脑肽食欲素-A和食欲素-B已知在脑室内给药时会诱导摄食行为，但对其他生理功能知之甚少。肾交感神经在体液和循环系统的动态平衡中起着重要作用。我们观察了脑室注射食欲素对清醒大鼠平均动脉压(MAP)、心率(HR)、肾交感神经活动(RSNA)和血浆儿茶酚胺的影响。食欲素A(0.3、3.0nmol)可使MAP(94.3+/-0.7至101.9+/-0.7 mm Hg)和RSNA(分别为2 8.0+/-7.0和5 7.9+/-12.3%)升高(分别为94.3+/-0.7至101.9+/-0.7 mm Hg和93.1+/-1.1至108.3+/-0.8 mm Hg)。同样，食欲素-B(0.3，3.0nmol)使MAP升高(分别为93.9+/-0.9至97.9+/-0.9毫米汞柱和94.5+/-1.1至105.3+/-1.7毫米汞柱)。3.0nmoL的食欲素-A和食欲素-B也使心率增加。在其他清醒的大鼠中，高剂量的增食欲素-A和-B会增加血浆去甲肾上腺素。血浆肾上腺素仅在大剂量增食欲素-A的作用下升高。这些结果表明，中枢食欲素调节交感神经活动，影响心血管功能。
The novel hypothalamic peptides orexin-A and orexin-B are known to induce feeding behavior when administered intracerebroventricularly, but little is known about other physiological functions. The renal sympathetic nerves play important roles in the homeostasis of body fluids and the circulatory system. We examined the effects of intracerebroventricularly administered orexins on mean arterial pressure (MAP), heart rate (HR), renal sympathetic nerve activity (RSNA), and plasma catecholamine in conscious rats. Orexin-A(0.3, 3.0 nmol) provoked an increase in MAP (94.3 +/- 0.7 to 101.9 +/- 0.7 mmHg and 93.1 +/- 1.1 to 108.3 +/- 0.8 mmHg, respectively) and RSNA(28.0 +/- 7.0 and 57.9 +/- 12.3%, respectively). Similarly, orexin-B (0.3, 3.0 nmol) increased MAP (93.9 +/- 0.9 to 97.9 +/- 0.9 mmHg and 94.5 +/- 1.1 to 105.3 +/- 1.7 mmHg, respectively). Orexin-A and -B at 3.0 nmol also increased HR. In other conscious rats, a high dose of orexin-A and -B increased plasma norepinephrine. Plasma epinephrine only increased with a high dose of orexin-A. These results indicate that central orexins regulate sympathetic nerve activity and affect cardiovascular functions.