在帚尾袋貂中，甘丙肽而非神经肽Y对心脏迷走神经作用的抑制。

Inhibition of cardiac vagal action by galanin but not neuropeptide Y in the brush-tailed possum Trichosurus vulpecula.

Courtice G P, Potter E K, McCloskey D I

School of Physiology and Pharmacology, University of New South Wales, Kensington, Sydney, Australia.

J Physiol. 1993 Feb;461:379-86. doi: 10.1113/jphysiol.1993.sp019518.

Abstract

Stimulation of the right cardiac sympathetic nerve for 2 min at 16 Hz in the presence of either beta- or alpha- and beta-adrenoceptor blockade evoked attenuation of cardiac vagal action in eight possums: 31.3 +/- 10.3% maximum inhibition of cardiac vagal action on prolonging pulse interval, with a time to half-recovery of 4.9 +/- 1.1 min. 2. Intravenous injection of galanin (2-3.5 nmol kg-1) evoked similar inhibition of cardiac vagal action: 41.3 +/- 4.1% maximum inhibition of cardiac vagal action on pulse interval, with a time to half-recovery of 13.4 +/- 2.3 min. 3. Intravenous injection of neuropeptide Y (NPY) at greater molar doses (6.5-10 nmol kg-1) caused no inhibition of cardiac vagal action. 4. The galanin injections caused a powerful pressor response: 57.1 +/- 4.9 mmHg increase in systolic blood pressure. NPY caused a smaller pressor response, despite administration of higher molar doses: 36.7 +/- 3.0 mmHg increase in systolic blood pressure. 5. In the possum, galanin but not NPY can mimic the effects of cardiac sympathetic nerve stimulation on vagal action. Galanin also causes large pressor effects.

摘要

在存在β-肾上腺素能受体阻滞剂或α-和β-肾上腺素能受体阻滞剂的情况下，以16Hz频率刺激右侧心脏交感神经2分钟，可使8只负鼠的心脏迷走神经作用减弱：在延长脉搏间期方面，心脏迷走神经作用的最大抑制率为31.3±10.3%，恢复至半数效应的时间为4.9±1.1分钟。2. 静脉注射甘丙肽（2 - 3.5 nmol/kg）可引起类似的心脏迷走神经作用抑制：在脉搏间期方面，心脏迷走神经作用的最大抑制率为41.3±4.1%，恢复至半数效应的时间为13.4±2.3分钟。3. 静脉注射更高摩尔剂量（6.5 - 10 nmol/kg）的神经肽Y（NPY）未引起心脏迷走神经作用的抑制。4. 注射甘丙肽引起强烈的升压反应：收缩压升高57.1±4.9 mmHg。尽管给予了更高的摩尔剂量，NPY引起的升压反应较小：收缩压升高36.7±3.0 mmHg。5. 在负鼠中，甘丙肽而非NPY可模拟心脏交感神经刺激对迷走神经作用的影响。甘丙肽还会引起较大的升压效应。