Influence of the thyroid state on the calcium transient in ventricular muscle.
Influence of the thyroid state on the calcium transient in ventricular muscle.
复制标题
甲状腺状态对心室肌钙瞬变的影响。
DOI：
10.1007/bf00580665
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Morgan,JP
中科院分区：
文献类型：
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作者：
MacKinnon,R;Morgan,JP
本研究的目的是确定甲状腺激素对哺乳动物心室肌张力发展和细胞内钙瞬变的影响。通过皮下注射甲状腺素（每天0.3 mg/kg，持续2-3周）诱导雪貂出现甲状腺功能亢进（H）状态。年龄匹配对照组（C）的一半注射溶媒。通过化学方法将水母发光蛋白负载到雪貂乳头肌细胞中。以0.33 Hz刺激肌肉，并在30°C下同时记录等长张力和钙瞬变。C组（n=8）和H组（n=9）的峰值等长张力（mN/mm 2（±SD））分别为15.4±7.2和16.2±7.9。与C相比，H中达到峰值张力的时间和从峰值张力到80%松弛的时间分别减少了22%和28%。刺激后，C和H的钙瞬变分别在56±6 ms和47±5 ms达到最大值。C和H的峰值钙瞬变衰减80%的时间分别为95±8 ms和68±5 ms。比较了钙瞬变峰处水母发光蛋白发光与计算的最大发光Lmax的比率，它们没有差异。在22°C下，C（n=4）和H（n=3）中的Log（L/Lmax）分别为−3.3±0.1和−3.4±0.3。这些结果表明，甲状腺状态影响钙瞬变的时间过程，并与甲状腺功能亢进状态下观察到的收缩持续时间的缩短一致。
The purpose of this study was to determine the influence of thyroid hormone on tension development and the intracellular calcium transient in mammalian ventricular muscle. A hyperthyroid (H) state was induced in ferrets by subcutaneous injection ofl-thyroxine, 0.3 mg/kg daily, for 2–3 weeks. One-half of the age matched control group (C) were injected with vehicle. Aequorin was loaded into the cells of ferret papillary muscles by a chemical procedure. The muscles were stimulated at 0.33 Hz and isometric tension and the calcium transient were simultaneously recorded at 30°C. Peak isometric tension in mN/mm2(±SD) was 15.4±7.2 and 16.2±7.9 for C (n=8) and H (n=9) respectively. The time to peak tension and time to 80% relaxation from peak of tension were reduced by 22% and 28% respectively in H compared to C. After stimulation, the calcium transient reached a maximum in 56±6 ms in C and in 47±5 ms in H. The time to 80% decay of the peak calcium transient was 95±8 ms and 68±5 ms for C and H respectively. The ratio of the aequorin luminescence at the peak of the calcium transient over the calculated maximum luminescence,Lmax, were compared and they were not different. At 22°C Log (L/Lmax) was −3.3±0.1 in C (n=4) and −3.4±0.3 in H (n=3). These results indicate that the thyroid state influences the time course of the calcium transient and are consistent with the abbreviation in the duration of contraction that is observed in the hyperthyroid state.