Interaction of thyroid hormone and functional overload on skeletal muscle isomyosin expression.
Interaction of thyroid hormone and functional overload on skeletal muscle isomyosin expression.
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甲状腺激素和功能超负荷对骨骼肌异肌球蛋白表达的相互作用。
DOI：
10.1152/jappl.1994.77.2.621
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Baldwin,KM
中科院分区：
文献类型：
--
作者：
Swoap,SJ;Haddad,F;Caiozzo,VJ;Herrick,RE;McCue,SA;Baldwin,KM
本研究从蛋白质和mRNA水平研究了外源性甲状腺激素3，5，3‘-三碘甲状腺原氨酸(T3)和功能超负荷对骨骼肌肌球蛋白重链(MHC)表达的影响。实验动物分为正常对照组、超负荷对照组、甲亢对照组和甲亢+超负荷组。通过手术切除大鼠比目鱼肌和腓肠肌的增效剂(比目鱼肌和腓肠肌)造成大鼠足底超负荷，并通过注射T_3(350微克/公斤，隔日一次)造成甲亢。超负荷8wk后，两个超负荷组的肌肉增大幅度均为53%(P<；0.05)。同时，超载对照组I型和IIa型MHC的相对含量分别增加了330%和82%，IIx和IIb型MHC的相对含量分别下降了16%和44%(P<；0.05与正常对照组相比)。这些MHC的相对和绝对mRNA含量的变化与蛋白质反应是平行的。外源性T3在蛋白和mRNA水平上完全逆转了I型MHC的上调和IIx的下调(P<；0.05)。然而，T3在钝化超负荷引起的IIb MHC下调和IIa MHC(蛋白质和mRNA)上调方面只有部分效果。
This study examined the interaction of exogenous thyroid hormone 3,5,3′-triiodothyronine (T3) and functional overload on skeletal muscle myosin heavy chain (MHC) expression, studied at both the protein and mRNA level of analysis. Animals were allocated to the following groups: 1) normal control, 2) overload control, 3) hyperthyroid control, and 4) hyperthyroid+overload. Overload of the rat plantaris was accomplished by surgical removal of its synergists (soleus and gastrocnemius), and the animals were made hyperthyroid by injections of T3 (350 micrograms/kg every other day). After overload of 8 wk, muscle enlargement occurred by 53% for both overload groups (P < 0.05). This was accompanied by a 330 and 82% increase in the relative content of type I and IIa MHC, respectively, and a corresponding decrease by 16 and 44% in type IIx and IIb MHC, respectively, in the overload control group (P < 0.05 vs. normal control). Changes in the relative and absolute content of mRNA for these MHCs paralleled the protein response. Exogenous T3 completely reversed the upregulation of type I MHC and the downregulation of type IIx associated with overload at both the protein and mRNA level (P < 0.05). However, T3 was only partially effective in blunting the downregulation of IIb MHC and the upregulation of IIa MHC (protein and mRNA) accompanying the overload.(ABSTRACT TRUNCATED AT 250 WORDS)