大鼠下丘脑弓状核降压效应的外周机制初探

Fall in Blood Pressure by Electrostimulation of Arcuate Nucleus: Mediation by Inhibition of Spinal Sympathetic Activities in Rat

采用切断大鼠双侧迷走神经或横断脊髓Ｃ１水平以阻断迷走神经传出冲动或脊髓交感活动，初步探讨自主神经系统在下丘脑弓状核降压效应中的作用。实验发现，切断双侧迷走神经对弓状核降压效应无明显影响；Ｃ１水平横断脊髓后，弓状核降压效应即被取消（Ｐ＜０００１）。结果表明，弓状核降压效应与迷走活动无关，但依赖脊髓的完整性。提示弓状核降压效应可能是脊髓交感活动减弱的结果。

Rats were sacrificed in the experiment to investigate the effects of the bilateral vagotomy and the spinal transection at the C 1 level on the depressor response by stimulating arcuate nucleus(ARC) electrically. It was found that the bilateral vagotomy exerted no influence on the ARC depressor effect, whereas the C 1 spinal transection eliminated the ARC effect. It is quite evident that the integrity of the spinal cord is neccessary for the ARC depressor effect which has nothing to do with the bilateral vagotomy. Our results suggest that the ARC depressor effect may be mediated by its inhibition of the sympathetic activities in the spinal cord.