室旁核在刺激猫肾神经传入纤维引起的血压效应中的作用

ROLE OF PARAVENTRICULAR NUCLEUS OF HYPOTHALAMUS IN PRESSOR RESPONSE TO STIMULATION OF RENAL AFFERENT NERVE IN CATS

本研究的目的是在氯醛糖麻醉、颈动脉窦、主动脉弓去神经和切断迷走神经的猫中探讨室旁核和室旁核α_1肾上腺素受体在刺激肾神经传入纤维引起的升压反应中的作用。刺激肾神经中枢端可引起动脉血压明显升高。这种血压升高由两个成分组成。第一成分可被植物性神经阻断剂六烃季铵和阿托品所阻断,第二成分不能被植物性神经阻断剂所阻断。双侧室旁核毁损后,植物性神经阻断前、后刺激肾神经中枢端引起的升压反应都明显减弱。侧脑室和室旁核微量注射α_1肾上腺素受体拮抗剂哌唑嗪,可显著抑制刺激肾神经传入纤维引起的升压反应。这些结果表明,室旁核和中枢的,尤其在室旁核的α_1肾上腺素受体在刺激肾神经传入纤维引起的升压反应中起重要作用。

The purpose of this study is to investigate the role of paraventricular nucleusof the hypothalamus(PVN)and α_1 adrenergic receptor of PVN in the pressor res-ponses to stimulation of renal afferent nerve in α_1-chloralose-anesthetized catswith carotid sinoaortic denervation and vagotomy.The pressor response to stimu-lation of renal afferent nerve consisted of a primary and a second components.Theprimary component response was completely blocked while the second componentwas not blocked by autonomic blocking agents(hexomethonium and atropine).Bilateral lesions of PVN greatly attenuated the pressor response before and afterautonomic blockade.Intracerebroventricular and PVN injection α_1,adrenergicantagonist(prazosin)significantly decreased in the pressor response to stimulationof renal afferent nerve.These results indicate that paraventricular nucleus of thehypothalamus and α_1 adrenergic receptors in central nervous system,especiallyin PVN,play an important role in the pressor responses to stimulation of renal af-ferent nerve.