Central ghrelin modulates sympathetic activity in conscious rabbits
Central ghrelin modulates sympathetic activity in conscious rabbits
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DOI：
10.1161/01.hyp.0000035395.51441.10
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发表时间：
2002-11-01
期刊：
影响因子：
8.3
通讯作者：
Lida, M
中科院分区：
文献类型：
--
作者：
Matsumura, K;Tsuchihashi, T;Lida, M
胃饥饿素是一种原从胃中分离出来的促氧肽。静脉注射胃饥饿素可以引起动脉压的降低，而心率（HR）没有明显变化，这表明胃饥饿素可能作用于中枢神经系统来调节交感神经活动。本研究的目的是确定胃饥饿素对有意识兔子心血管和交感反应的中心作用。静脉注射胃饥饿素引起动脉压和心率呈剂量相关性降低，而肾交感神经活动无明显变化。另一方面，脑室内注射1nmol胃饥饿素可降低动脉压、HR和肾交感神经活动。在脑室内注射1nmol胃饥饿素后50分钟和40分钟，分别观察到平均动脉压和肾交感神经活动的峰值降压或交感神经抑制反应（-19.0 +/- 1.5 mm Hg和-43.3 +/- 5.4%）。此外，脑室内注入胃饥饿素的亚抑制剂量（0.3 nmol/150 muL /小时）与载药输注相比，显著增强了肾交感神经活动和HR评估的压力反射敏感性(G(max)；- 17.8 +/- 3.1 vs -9.4 +/- 1.6%/mm Hg， P
Ghrelin is an orexigenic peptide originally isolated from the stomach. Intravenous administration of ghrelin has been shown to elicit a decrease in arterial pressure without a significant change in heart rate (HR), suggesting that ghrelin may act on the central nervous system to modulate sympathetic activity. The aim of the present study was to determine the central effects of ghrelin on cardiovascular and sympathetic responses in conscious rabbits. Intravenous injection of ghrelin elicited dose-related decreases in arterial pressure and HR, without a significant change in renal sympathetic nerve activity. On the other hand, intracerebroventricular injection of 1 nmol of ghrelin decreased arterial pressure, HR, and renal sympathetic nerve activity. Peak depressor or sympathoinhibitory responses of mean arterial pressure and renal sympathetic nerve activity (-19.0 +/- 1.5 mm Hg and -43.3 +/- 5.4%) were observed at 50 and 40 minutes, respectively, after intracerebroventricular injection of 1 nmol of ghrelin. Furthermore, a subdepressor dose of intracerebroventricular infusion of ghrelin (0.3 nmol/150 muL per hour) significantly augmented the baroreflex sensitivities assessed by renal sympathetic nerve activity and HR compared with those of vehicle infusion (G(max); - 17.8 +/- 3.1 versus -9.4 +/- 1.6%/mm Hg, P