Thyroid calorigenesis in isolated, perfused rat liver: minor role of active sodium‐potassium transport.
Thyroid calorigenesis in isolated, perfused rat liver: minor role of active sodium‐potassium transport.
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离体灌注大鼠肝脏中的甲状腺热量生成：活性钠钾转运的次要作用。
DOI：
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发表时间：
1977
期刊：
影响因子：
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通讯作者：
L. Sestoft
中科院分区：
文献类型：
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作者：
M. Folke;L. Sestoft
1.在禁食正常大鼠和三碘甲状腺原氨酸（T3）处理大鼠的离体肝脏非再循环灌注过程中，在37 ℃下检查哇巴因对肝脏氧摄取、细胞膜电位和Na-K转运的影响。灌注液为含有白蛋白和牛红细胞的Krebs-Ringer碳酸氢盐缓冲液。2. T3治疗使肝脏氧摄取率增加30%（即每克肝脏增加0 - 83（微摩尔/分钟））。3.在转换为含有2 - 5 mM哇巴因的灌注液后，在两种甲状腺状态下，4 - 5 mV去极化和最大肝脏K净释放率和Na摄取率均在2分钟内发生。这些变化并不伴随着肝氧摄取率的任何显著变化。4. T3处理使哇巴因给药后K的最大净通量增加29%（即每克肝脏增加0 - 52（μ当量/min））。T3诱导的Na净通量增加（19%）未达到统计学显著性。5.在任一甲状腺状态下，计算观察到的Na和K的被动通量，以观察到的肝脏摄氧率的5 - 6%为代价，通过主动通量平衡。6.结果表明，甲状腺功能亢进症可能会提高肝脏Na‐K转运的速率，但由于这一过程的能量消耗似乎太小，无法对灌注大鼠肝脏中的甲状腺产热做出任何重要贡献。
1. The effects of ouabain on hepatic oxygen uptake, cell membrane potential, and Na‐K transport were examined at 37 degrees C during non‐recirculating perfusion of isolated livers from fasted normal rats and rats treated with triiodothyronine (T3). The perfusate was Krebs‐Ringer bicarbonate buffer containing albumin and bovine erythrocytes. 2. Treatment with T3 increased the rate of hepatic oxygen uptake by 30% (i.e. by 0‐83 (micromole/min) per gram liver). 3. After shifting to perfusate containing 2‐5 mM ouabain, a 4‐5 mV depolarization and maximal rates of net hepatic K release and Na uptake occurred within 2 min in both thyroid states. These changes were not accompanied by any significant change in the rates of hepatic oxygen uptake. 4. T3‐treatment increased the maximal, post‐ouabain net flux of K by 29% (i.e. by 0‐52 (muequiv/min) per gram liver). The T3‐indlced increase in the net flux of Na (19%) did not achieve statistical significance. 5. In either thyroid state, the observed passive fluxes of Na and K were calculated to be balanced by active vluxes at the expense of 5‐6% of the observed rate of hepatic oxygen uptake. 6. The results indicate that hyperthyroidism may enhance the rate of hepatic Na‐K transport, but the energy expenditure due to this process appears to be too small to make any important contribution to thyroid calorigenesis in perfused rat liver.