EFFECTS OF CALCIUM-CHANNEL BLOCKERS ON ISOLATED CAROTID BARORECEPTORS AND BAROREFLEX
EFFECTS OF CALCIUM-CHANNEL BLOCKERS ON ISOLATED CAROTID BARORECEPTORS AND BAROREFLEX
复制标题
DOI：
10.1152/ajpheart.1983.245.4.h653
复制
发表时间：
1983-01-01
影响因子：
--
通讯作者：
ABBOUD, FM
中科院分区：
文献类型：
--
作者：
HEESCH, CM;MILLER, BM;ABBOUD, FM
本文研究了钙拮抗剂硝苯地平和维拉帕米对颈动脉窦压力感受器和压力反射的影响。将犬左侧颈动脉窦区血管分离并充满含氧生理盐溶液。在不含药物、10 μ g/ml硝苯地平（n = 6）或5 μ g/ml维拉帕米（n = 5）的溶液中浸泡颈动脉窦区域后，对于50-200 mm Hg的窦压，从颈动脉窦神经记录稳态多单位活动。将颈动脉窦神经活动（最大对照的%）与颈动脉窦压力相关的曲线的斜率为对照，0.81 ± 0.95。硝苯地平1.29 ± 0.06。维拉帕米0.48 ±。0.06%/mm Hg，表明硝苯地平增加和维拉帕米降低颈动脉窦压力感受器的敏感性。双侧颈动脉窦隔离（颈动脉窦曲线完整）的其他曲线表明，硝苯地平增强和维拉帕米衰减颈动脉压力反射控制肾交感神经活动。在离体颈动脉窦中产生的压力-容积曲线表明，对平滑肌的影响不能解释2种Ca 2+拮抗剂的相反作用。从生理溶液中省略Ca 2+导致颈动脉窦神经活动增加，维拉帕米而不是硝苯地平阻断了这种作用。维拉帕米，而不是硝苯地平，抑制藜芦碱诱导的（Na+依赖）兴奋颈动脉压力感受器。硝苯地平对颈动脉窦压力感受器的兴奋作用依赖于Ca 2+机制;维拉帕米的抑制作用可能主要是由于干扰内向Na+电流。
Effects of the Ca antagonists, nifedipine and verapamil, on the carotid sinus baroreceptors and baroreflex were studied. The left carotid sinus region in dogs was vascularly isolated and filled with oxygenated physiological salt solution. Steady-state multiunit activity was recorded from the carotid sinus nerve for sinus pressures of 50-200 mm Hg after bathing the carotid sinus region in a solution containing no drug, 10 .mu.g/ml nifedipine (n = 6) or 5 .mu.g/ml verapamil (n = 5). The slopes of curves relating carotid sinus nerve activity (% of maximum control) to carotid sinus pressure were control, 0.81 .+-. 0.06; nifedipine, 1.29 .+-. 0.14: and verapamil, 0.48 .+-. 0.06%/mm Hg, indicating that nifedipine increased and verapamil decreased sensitivity of the carotid sinus baroreceptors. Additional curves with bilateral carotid sinus isolation (carotid sinus curves intact) indicated that nifedipine enhanced and verapamil attenuated carotid baroreflex control of renal sympathetic nerve activity. Pressure-volume curves generated in the isolated carotid sinus showed that effects on smooth muscle do not account for the opposing effects of the 2 Ca2+ antagonists. Omitting Ca2+ from the physiological solution resulted in increased carotid sinus nerve activity, an effect blocked by verapamil but not nifedipine. Verapamil, but not nifedipine, inhibited veratrine-induced (Na+-dependent) excitation of carotid baroreceptors. Excitatory effects of nifedipine on the carotid sinus baroreceptors are dependent on Ca2+ mechanisms; inhibitory effects of verapamil may be due mainly to interference with the inward Na+ current.