Guo G B, Schmid P G, Abboud F M
Am J Physiol. 1986 Sep;251(3 Pt 2):H644-55. doi: 10.1152/ajpheart.1986.251.3.H644.
We recently reported that intravenous vasopressin in anesthetized rabbits facilitates baroreflex inhibition of lumbar sympathetic nerve activity. The purpose of this study was to determine the possible sites of this facilitation. We found that intravenous infusion of vasopressin (16-32 mU X kg-1 X min-1) caused greater inhibition of lumbar sympathetic nerve activity than did phenylephrine for a given increase in aortic baroreceptor activity, suggesting a "central" action of vasopressin. A central action was supported also by the observation that the carotid baroreflex inhibition of lumbar sympathetic nerve activity was augmented by intravenous infusion of vasopressin when the carotid sinuses were isolated, filled with saline, and distended (aortic depressor and vagal nerves were cut). On the other hand, vasopressin also facilitated baroreflex inhibition of lumbar sympathetic nerve activity through an influence on arterial baroreceptors, because intravenous vasopressin caused greater afferent activity of the aortic depressor nerve per unit rise in arterial pressure than did phenylephrine. In a separate group of rabbits, intravenous infusion of vasopressin also elevated the level of afferent aortic depressor activity during increases in arterial pressure induced by intra-aortic balloon inflation. Furthermore, when vasopressin was confined to the isolated carotid sinuses, the reflex inhibition of lumbar sympathetic nerve activity during distension of carotid sinuses was augmented. We conclude that circulating vasopressin facilitates baroreflex inhibition of sympathetic nerve activity through a central nervous system action as well as through an effect on arterial baroreceptors.
我们最近报道，在麻醉兔中静脉注射血管加压素可促进压力反射对腰交感神经活动的抑制。本研究的目的是确定这种促进作用可能的位点。我们发现，对于给定的主动脉压力感受器活动增加，静脉输注血管加压素（16 - 32 mU·kg⁻¹·min⁻¹）比去氧肾上腺素能更有效地抑制腰交感神经活动，提示血管加压素存在“中枢”作用。当分离颈动脉窦、用盐水充盈并扩张（切断主动脉降压神经和迷走神经）时，静脉输注血管加压素可增强颈动脉压力反射对腰交感神经活动的抑制，这一观察结果也支持了中枢作用。另一方面，血管加压素还通过影响动脉压力感受器促进压力反射对腰交感神经活动的抑制，因为静脉注射血管加压素比去氧肾上腺素在动脉血压每升高单位时能引起更大的主动脉降压神经传入活动。在另一组兔中，在主动脉内球囊充气诱导动脉血压升高期间，静脉输注血管加压素也提高了主动脉降压传入活动水平。此外，当血管加压素局限于分离的颈动脉窦时，颈动脉窦扩张期间腰交感神经活动的反射性抑制增强。我们得出结论，循环中的血管加压素通过中枢神经系统作用以及对动脉压力感受器的影响促进压力反射对交感神经活动的抑制。
