THYROID THERMOGENESIS - RELATIONSHIPS BETWEEN NA+-DEPENDENT RESPIRATION AND NA+ + K+ ADENOSINE TRIPHOSPHATASE-ACTIVITY IN RAT SKELETAL-MUSCLE
THYROID THERMOGENESIS - RELATIONSHIPS BETWEEN NA+-DEPENDENT RESPIRATION AND NA+ + K+ ADENOSINE TRIPHOSPHATASE-ACTIVITY IN RAT SKELETAL-MUSCLE
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DOI：
10.1172/jci108288
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发表时间：
1976-01-01
影响因子：
15.9
通讯作者：
EDELMAN, IS
中科院分区：
文献类型：
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作者：
ASANO, Y;LIBERMAN, UA;EDELMAN, IS
在大鼠骨骼肌中检查了甲状腺状态对 QO2、QO2 (t) 和 NaK-ATP 酶活性的影响。 QO2(t)（即 Na+ 运输依赖性呼吸）是用哇巴因或补充有 K+ 的无 Na+ 培养基估计的。与哇巴因对离子组成的影响相反，在无Na+的培养基中，细胞内K+维持在约125meq/L，细胞内Na+几乎为零。 QO2(t) 的估计值与组织离子浓度的显着差异无关。 QO2(t)的增加占从甲状腺功能减退到甲状腺功能正常状态转变过程中QO2增加的47%，占从甲状腺功能正常到甲状腺功能亢进状态转变过程中QO2增加的84%。甲状腺切除术使微粒体部分的 NaK-ATP 酶活性（以每毫克蛋白质表示）降低了 32%；注射三碘甲状腺原氨酸（T3）使最初甲状腺功能减退的大鼠的这种活性增加了 75%，而最初甲状腺功能正常的大鼠则增加了 26%。甲状腺切除术后血清 Ca 和 Pi 浓度显着下降。 T3 的施用导致血清 Ca 进一步下降，血清 Ps 浓度显着增加。在 131I 治疗的大鼠中也观察到类似的效果，但血清 Ca 下降的幅度较小。 T3 对 131I 消融大鼠和手术甲状腺切除大鼠骨骼肌 QO2、QO2(t) 和 NaK-ATPase 活性的影响无法区分。在甲状腺切除或甲状腺功能正常的大鼠中，给予重复剂量的 T3、QO2(t) 和 NaA-ATPase 活性成比例增加。在甲状腺切除大鼠中注射单剂量 T3（10、50 或 250 微克/100 克体重）时，QO2(t) 随 NaK-ATP 酶活性呈线性增加。使用 ATP 生成系统评估 NaK-ATP 酶活性的动力学。 T3 引起 Vmax 显着增加，而 ATP 的 Km 没有变化。
The effect of thyroid status on QO2, QO2 (t) and NaK-ATPase activity was examined in rat skeletal muscle. QO2(t) (i.e. Na+-transport-dependent respiration) was estimated with ouabain or Na+-free media supplemented with K+. In contrast to the effects of ouabain on ion composition, intracellular K+ was maintained at about 125 meq/liter, and intracellular Na+ was almost nil in the Na+-free media. The estimates of QO2(t) were independent of the considerable differences in tissue ion concentrations. The increase in QO2(t) account for 47% of the increase in QO2 in the transition from the hypothyroid to the euthyroid state and 84% of the increase in the transition from the euthyroid to the hyperthyroid state. Surgical thyroidectomy lowered NaK-ATPase activity of the microsomal fraction (expressed per milligram protein) 32%; injections of triodothyronine (T3) increased this activity 75% in initially hypothyroid rats and 26% in initially euthyroid rats. Thyroidectomy was attended by significant falls in serum Ca and Pi concentrations. Administration of T3 resulted in further declines in serum Ca and marked increases in serum Ps concentrations. Similar effects were seen in 131I-treated rats, but the magnitude of the declines in serum Ca were less. The effects of T3 on QO2, QO2(t), and NaK-ATPase activity of skeletal muscle were indistinguishable in the 131I-ablated and surgically thyroidectomized rats. In thyroidectomized or euthyroid rats given repeated doses of T3, QO2(t) and NaA-ATPase activity increased proportionately. In thyroidectomized rats injected with single doses of T3, either 10, 50, or 250 mug/100 g body wt, QO2(t) increased linearly with NaK-ATPase activity. The kinetics of the NaK-ATPase activity was assessed with an ATP-generating system. T3 elicited a significant increase in Vmax with no change in Km for ATP.