Effects of thyroid hormone on cardiac size and myosin content of the heterotopically transplanted rat heart.
Effects of thyroid hormone on cardiac size and myosin content of the heterotopically transplanted rat heart.
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甲状腺激素对异位移植大鼠心脏大小和肌球蛋白含量的影响。
DOI：
10.1172/jci112488
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Hong,C
中科院分区：
文献类型：
--
作者：
Klein,I;Hong,C
肾下异位心脏同种异体移植保持结构和功能的完整性。我们利用该移植模型进一步探讨了甲状腺激素诱导心肌肥大的机制。与对照组相比，每天给予1-甲状腺素(T4)10微克/只动物，心脏总重量显著增加30%，原位心脏肌球蛋白含量增加40%。相反，T4治疗对异位非工作心脏的心脏重量、蛋白质含量、蛋白质合成速率或计算的肌球蛋白含量没有影响。异位心脏显示V1肌球蛋白同工酶的百分比从95%显著下降到61%。这种转变发生在甲状腺功能正常的动物身上，但可以通过T4治疗来阻止。这些结果表明，甲状腺激素诱导的心肌肥厚是通过心脏做功的改变间接介导的。肌球蛋白同工酶的表达可以通过工作负荷的变化来改变，但仍然对甲状腺激素水平的增加有反应。
Infrarenal heterotopic cardiac isografts maintain structural and functional integrity. We have used this transplantation model to further explore the mechanisms of thyroid hormone-induced cardiac hypertrophy. Thyroid hormone administration, 1-thyroxine (T4) 10 micrograms/animal per d, led to a significant 30% increase in total heart weight and a 40% increase in the myosin content of the in situ heart when compared with control. In contrast, T4 treatment was without effect on the heart weight, protein content, rate of protein synthesis, or calculated myosin content of the heterotopic, nonworking heart. Heterotopic hearts demonstrated a significant decrease in the percentage of the V1 myosin isoenzyme from 95% to 61%. This shift occurred in euthyroid animals but was prevented by T4 treatment. These results suggest that thyroxine-induced cardiac hypertrophy is mediated indirectly via changes in cardiac work. Myosin isoenzyme expression can be altered by changes in work load but is still responsive to increased levels of thyroid hormone.