摘要
目的 :研究NO前体L Arg微量注入大鼠延髓尾端加压区 (CPA)对心血管活动的影响并探讨其可能的机制。方法 :采用延髓腹外侧部微量注射法 ,以整体灌流肾为模型观察与NO代谢有关的试剂对心血管活动的影响。结果 :①CPA内微量注入L Arg(60～ 10 0nmol) ,动脉血压与心率呈剂量依赖性下降 ,肾灌流压下降 ,与生理盐水对照 ,差异有显著意义 ;②预先在CPA内注入鸟苷酸环化酶抑制剂甲基蓝可取消L Arg的降压降肾灌流压作用 ;③CPA内注入L Glu ,AP上升。如预先注入L Arg后 5min再注入L Glu ,L Glu的升压效应被衰减 ,其衰减程度与L Arg是剂量依赖性关系。结论 :CPA内的L Arg NO通路参与延髓心血管中枢对AP的调控 。
Aim: To study the effect of microinjection L arginine, a precursor for the synthesis of nitric oxide into the functionally identified caudal pressor area (CPA) in ventral surface of medulla oblongata. Methods: Artery pressure (AP), renal perfusion pressure (RPP ) and heart rate were recorded to study the effects of microinjection of NO related drugs into CPA. Results:① Unilatera1 microinjection of L arginine (60～100 nmol) into CPA produced prominent dose related depressor and bradycardic effects and reduced renal perfusion pressure. ②Unilateral microinjection of L arginine (100 nmol) 3 min after microinjection of methylene blue (10 nmol ) into CPA did not significamly change AP and RPP.③Unilateral microinjection of L glutamate (350 nmol) into CPA elicited pressor effect which was significanly dose related attenuated by prior microinjection of L arginine (60～100 nmol) into the same area. Conclusion: Theses results suggest that L arginine NO pathway in the CPA participates in the central regulation of arterial pressure and may have a key role in the inhibiting of glutamatergic neurotransmission in the anesthetized rats.
出处
《中国应用生理学杂志》
CAS
CSCD
北大核心
2001年第3期267-270,共4页
Chinese Journal of Applied Physiology
