Bonham A C, Gutterman D D, Arthur J M, Marcus M L, Gebhart G F, Brody M J
Department of Pharmacology, University of Iowa, Iowa City 52242.
Circ Res. 1987 Nov;61(5 Pt 2):II42-6.
The central representation of neurogenically mediated coronary vasoconstriction produced by activation of the sympathetic nervous system was examined in anesthetized cats instrumented for continuous recording of coronary and femoral blood flows, arterial pressure, and heart rate. Electrical stimulation in a small region of perifornical lateral hypothalamus increased arterial pressure, heart rate, and coronary blood flow; following the administration of propranolol, a transient coronary vasoconstrictor response was unmasked. The response was mediated over the sympathetic nervous system since it was blocked by stellate ganglionectomy and by the alpha 1-adrenergic receptor antagonist prazosin. Projections to and from the lateral hypothalamic site were identified by using anterograde and retrograde pathway-tracing techniques. Paraventricular nucleus projected to lateral hypothalamus, which in turn made connections in periaqueductal gray with projections terminating in lateral reticular formation of medulla. Coronary vasoconstrictor responses qualitatively identical to those produced by hypothalamic stimulation were found with activation of paraventricular nucleus and lateral reticular formation. Interruption of neuronal transmission in the medullary site blocked the response produced by activation of hypothalamic site. These data demonstrate that coronary vasoconstriction mediated over the sympathetic nervous system can be elicited from an interconnected pathway that links sympathoexcitatory sites in forebrain and brainstem.
在麻醉的猫身上进行实验，通过仪器连续记录冠状动脉和股动脉血流、动脉血压及心率，以此研究交感神经系统激活所产生的神经源性介导的冠状动脉血管收缩的中枢表现。刺激穹窿周外侧下丘脑的一个小区域，会使动脉血压、心率及冠状动脉血流增加；给予普萘洛尔后，短暂的冠状动脉血管收缩反应便显现出来。该反应由交感神经系统介导，因为它会被星状神经节切除术及α1 -肾上腺素能受体拮抗剂哌唑嗪阻断。运用顺行和逆行示踪技术确定了下丘脑外侧部位的传入和传出投射。室旁核投射至下丘脑外侧，下丘脑外侧又与导水管周围灰质建立联系，其投射终止于延髓外侧网状结构。激活室旁核和外侧网状结构时，会出现与下丘脑刺激所产生的冠状动脉血管收缩反应在性质上相同的反应。阻断延髓部位的神经传递会阻碍下丘脑部位激活所产生的反应。这些数据表明，交感神经系统介导的冠状动脉血管收缩可由一条相互连接的通路引发，该通路连接了前脑和脑干中的交感兴奋部位。
