Godfraind T, Wibo M
Laboratoire de Pharmacologie, Université catholique de Louvain-en-Woluwe.
Bull Mem Acad R Med Belg. 1990;145(10):394-402; discussion 402-3.
We have studied the post-natal maturation of excitation-contraction coupling in rat ventricle by means of pharmacological agents that selectively modulate either Ca entry via voltage-dependent sarcolemmal channels (dihydropyridines) or Ca release from sarcoplasmic reticulum (ryanodine). We have investigated the effects of those agents on cardiac contractility, and we have used them as radioligands to examine the properties of their receptors. Our results show that, after birth, dihydropyridine receptors (i.e. voltage-dependent Ca channels) redistribute to transverse tubules, in close proximity of terminal cisternae of sarcoplasmic reticulum. This redistribution favors the mechanism whereby, in adult ventricle, extracellular Ca entry triggers Ca release from sarcoplasmic reticulum.
我们通过使用能够选择性调节经由电压依赖性肌膜通道（二氢吡啶）的钙内流或肌浆网钙释放（ryanodine）的药物制剂，研究了大鼠心室兴奋-收缩偶联的产后成熟过程。我们研究了这些制剂对心脏收缩性的影响，并将它们用作放射性配体来检测其受体的特性。我们的结果表明，出生后，二氢吡啶受体（即电压依赖性钙通道）重新分布到横管，靠近肌浆网终末池。这种重新分布有利于成年心室中细胞外钙内流触发肌浆网钙释放的机制。
