地尔硫䓬对缺氧心肌力学性能的保护作用。

Protective effects of diltiazem on the mechanical performance of the hypoxic myocardium.

Cicogna A C, Padovani C R, Brooks W W, Schine L, Robinson K G, Conrad C H, Gaasch W H, Bing O H

Departamento de Clínica Médica, Faculdade de Medicina de Botucatu, Universidade Estadual de São Paulo, Brasil.

Braz J Med Biol Res. 1993 Aug;26(8):859-68.

Abstract

To determine whether diltiazem protects the hypoxic myocardium by reducing contractile work, we have compared the effects of diltiazem and quiescence on left ventricular (LV) papillary muscle subjected to hypoxia. Papillary muscles were obtained from male Charles River CD rats weighing 150-250 g. 2. Four groups of muscles were studied: control (N = 6), non-stimulation (N = 10), diltiazem 10(-4) M (N = 6) and diltiazem 10(-4) M plus non-stimulation (N = 10). 3. Isolated rat LV papillary muscles were studied in Krebs-Henseleit solution with a calcium concentration of 2.52 mM at 28 degrees C while contracting isometrically at a stimulation rate of 0.2 Hz. Resting tension and active isometric tension were measured. 4. Both diltiazem and quiescence significantly attenuated contracture tension during hypoxia (0.91 +/- 0.10 vs 2.26 +/- 0.49 g/mm2 for diltiazem vs control, and 0.55 +/- 0.18 vs 2.26 +/- 0.49 g/mm2 for quiescence vs control). Recovery of active tension was improved in the diltiazem groups during reoxygenation (4.16 +/- 0.42 vs 3.75 +/- 0.51, 3.53 +/- 0.15 vs 2.90 +/- 0.13, 5.84 +/- 0.33 vs 6.48 +/- 0.29 and 5.98 +/- 0.90 vs 7.67 +/- 0.68 g/mm2 for diltiazem, diltiazem non-stimulation, non-stimulation and control groups). 5. The results suggest that the protective effect of diltiazem during hypoxia was due to the reduction in energy demand of the myocardium.

摘要

为了确定地尔硫䓬是否通过减少收缩功来保护缺氧心肌，我们比较了地尔硫䓬和静息状态对遭受缺氧的左心室（LV）乳头肌的影响。乳头肌取自体重150 - 250克的雄性查尔斯河CD大鼠。2. 研究了四组肌肉：对照组（N = 6）、非刺激组（N = 10）、10(-4) M地尔硫䓬组（N = 6）和10(-4) M地尔硫䓬加非刺激组（N = 10）。3. 在28℃下，于钙浓度为2.52 mM的克雷布斯 - 亨塞尔特溶液中研究分离的大鼠LV乳头肌，同时以0.2 Hz的刺激频率进行等长收缩。测量静息张力和主动等长张力。4. 地尔硫䓬和静息状态均显著减弱了缺氧期间的挛缩张力（地尔硫䓬组与对照组相比为0.91±0.10对2.26±0.49 g/mm2，静息组与对照组相比为0.55±0.18对2.26±0.49 g/mm2）。复氧期间，地尔硫䓬组的主动张力恢复得到改善（地尔硫䓬组、地尔硫䓬非刺激组、非刺激组和对照组的主动张力恢复分别为4.16±0.42对3.75±0.51、3.53±0.15对2.90±0.13、5.84±0.33对6.48±0.29和5.98±0.90对7.67±0.68 g/mm2）。5. 结果表明，地尔硫䓬在缺氧期间的保护作用是由于心肌能量需求的降低。