Wu G T, Dong H, Liang Z J
Department of Pharmacology, School of Basic Medical Sciences, Shanghai Medical University, China.
Zhongguo Yao Li Xue Bao. 1995 May;16(3):239-42.
To investigate the cardiac actions of 2-[(diethylamino)acetyl]-1,2,3,4-tetrahydro-6, 7-dimethoxyl-1-[1'-(6"-methoxy-2"-naphthalenyl) ethyl]-isoquinoline (CPU57) by comparison with nifedipine and focus on its mechanism of actions.
The following were measured and recorded: 1) the rate and contraction of spontaneous beating of the guinea pigs right heart atrium, 2) the isometric tension of the electrically stimulated left heart atrium and the right papillary muscles.
CPU57 had negative inotropic and negative chronotropic actions in isolated heart of guinea pigs as the typical calcium antagonist, nifedipine. However, CPU57 0.01-100 mumol.L(-1) produced less cardiac inhibitory potency than nifedipine and had much stronger negative inotropic action than negative chronotropic action. The decrease in external CaCl2 concentration from 1.5 to 0.3 mmol.L(-1) or increase to 7.5 mmol.L(-1), potentiated or reduced respectively, the inhibitory action of CPU57 on the contraction in paced left heart atrium in normal CaCl2 solution. CPU57 1-10 mumol.L(-1) also inhibited contractile response to CaCl2 in paced left heart atrium with pD2' value of 4.77.
CPU57 has calcium antagonism on the heart of guinea pigs.
通过与硝苯地平比较，研究2-[(二乙氨基)乙酰基]-1,2,3,4-四氢-6,7-二甲氧基-1-[1'-(6''-甲氧基-2''-萘基)乙基]-异喹啉（CPU57）对心脏的作用，并着重探讨其作用机制。
测量并记录以下指标：1）豚鼠右心房自发搏动的速率和收缩情况；2）电刺激左心房和右乳头肌的等长张力。
与典型钙拮抗剂硝苯地平一样，CPU57对豚鼠离体心脏有负性肌力和负性频率作用。然而，CPU57在0.01 - 100μmol·L⁻¹浓度范围内产生的心脏抑制作用比硝苯地平弱，且负性肌力作用比负性频率作用更强。将细胞外氯化钙浓度从1.5mmol·L⁻¹降至0.3mmol·L⁻¹或升至7.5mmol·L⁻¹，分别增强或减弱了CPU57在正常氯化钙溶液中对起搏左心房收缩的抑制作用。CPU57在1 - 10μmol·L⁻¹浓度范围内也抑制了起搏左心房对氯化钙的收缩反应，其pD2'值为4.77。
CPU57对豚鼠心脏具有钙拮抗作用。
