Vornanen M
Comp Biochem Physiol A Comp Physiol. 1984;78(4):691-5. doi: 10.1016/0300-9629(84)90618-2.
The effects of 0.25-16.0 mM Ca2+ on the contractile force of isolated ventricular strips and sarcolemmal Ca2+-ATPase activity during postnatal development of the rat heart were studied. The half maximal concentrations for contractile activation of ventricular strips were 0.76 and 5.59 mM Ca2+ for adult and 3-day-old rats, respectively. The sensitivity towards Ca2+ began to change from newborn type to that of adult rat 2 weeks after birth and was almost completed after 4 weeks. No significant differences were found in half maximal activation of Ca2+-ATPase by Ca2+ between different age groups. Activation of contractility and Ca2+-ATPase by Ca2+ were linearly related in 30-day-old and adult rats but not in 3- and 10-day-old rats. The observed sensitivity change towards extracellular Ca2+ for contractile activation is suggested to be due to the development of transverse tubular system and sarcoplasmic reticulum during the first 4 weeks of postnatal development.
研究了0.25 - 16.0 mM钙离子对大鼠心脏出生后发育过程中离体心室肌条收缩力和肌膜钙离子 - ATP酶活性的影响。成年大鼠和3日龄大鼠心室肌条收缩激活的半数最大浓度分别为0.76 mM和5.59 mM钙离子。对钙离子的敏感性在出生后2周开始从新生类型转变为成年大鼠类型，并在4周后基本完成。不同年龄组之间钙离子对钙离子 - ATP酶半数最大激活无显著差异。在30日龄和成年大鼠中，钙离子对收缩力和钙离子 - ATP酶的激活呈线性相关，但在3日龄和10日龄大鼠中并非如此。观察到的收缩激活对细胞外钙离子敏感性的变化被认为是由于出生后发育的前4周横管系统和肌浆网的发育所致。
