Li Q P, Rao M R
Department of Cardiovascular Pharmacology, Nanjing Medical University.
Yao Xue Xue Bao. 1995;30(1):21-6.
The hemodynamic changes of metoprolol (Met, 50 mg.kg-1.d-1, po, 3 wk) withdrawal for 1 day and the effects of nifedipine (Nif) and m-nifedipine (m-Nif) on these changes were observed in pressure overload hypertrophy in rats by abdominal aortic constriction for 4 wk. Both Nif and m-Nif (10 mg.kg-1.d-1, respectively, po, 3 wk) significantly attenuated the increase of MAP (from 14.3 +/- 2.3 to 12.9 +/- 2.3 and 11.3 +/- 2.4 kPa, respectively, n = 6-7, P < 0.05) and decrease the abnormal development of systolic function of left ventricle after Met withdrawal. Radioreceptor assay indicates that Nif and m-Nif can prevent the up-regulation of myocardium beta-receptors in left ventricular hypertrophy and large dose of Met exposure for a long time. These results suggest that calcium antagonists administered with beta-blockers can prevent beta-receptor blocker withdrawal syndrome.
通过腹主动脉缩窄4周建立大鼠压力超负荷肥大模型，观察美托洛尔（Met，50 mg·kg-1·d-1，口服，3周）撤药1天的血流动力学变化以及硝苯地平（Nif）和间硝苯地平（m-Nif）对这些变化的影响。Nif和m-Nif（分别为10 mg·kg-1·d-1，口服，3周）均显著减弱了撤药后平均动脉压的升高（分别从14.3±2.3降至12.9±2.3和11.3±2.4 kPa，n = 6 - 7，P < 0.05），并减轻了左心室收缩功能的异常发展。放射受体分析表明，Nif和m-Nif可防止左心室肥大和长期大剂量Met暴露后心肌β受体上调。这些结果提示，钙拮抗剂与β受体阻滞剂联用可预防β受体阻滞剂撤药综合征。
