Voci A, Demori I, Franzi A T, Fugassa E, Goglia F, Lanni A
Dipartimento di Biologia Sperimentale, Ambientale ed Applicata (DIBISAA), Sez. Fisiologia Generale e Comparata, Università degli Studi di Genova, C.so Europa 26, I-16132 Genoa, Italy.
Eur J Endocrinol. 2001 Sep;145(3):317-22. doi: 10.1530/eje.0.1450317.
The levels of uncoupling protein 2 (UCP2) mRNA and determinants of respiration (ATP synthesis, proton leak and non-mitochondrial respiration) were evaluated in Kupffer cells isolated from the livers of normal euthyroid, acute hyperthyroid and chronic hyperthyroid rats.
After liver perfusion, Kupffer cells were purified by density-gradient centrifugation followed by counterflow centrifugal elutriation. UCP2 mRNA levels were measured by Northern blot and respiratory parameters by polarographic method.
In cells isolated from hyperthyroid (tri-iodothyronine (T(3))-treated) rats, the effect of T(3) treatment on the UCP2 mRNA level varied: it was more than doubled (P<0.05) in acutely T(3)-treated rats but, after chronic (3-week) T(3) treatment, it was only 30% (not statistically significant) above the control (euthyroid) level. In Kupffer cells from the livers of chronic hyperthyroid rats, we observed an increase in total respiration rate, with an increase in the percentage attributable to the proton leak and a corresponding decrease in the percentage attributable to ATP synthesis (no alteration was observed in the percentage attributable to non-mitochondrial respiration). In the acute hyperthyroid rats, no significant differences were observed in any of the respiratory parameters, although they all tended to increase.
These data are indicative of a possible uncoupling effect of UCP2 in Kupffer cells. T(3), by enhancing the expression of UCP2, could play a role in the energy homeostasis of these cells.
评估从正常甲状腺功能正常、急性甲状腺功能亢进和慢性甲状腺功能亢进大鼠肝脏分离的库普弗细胞中解偶联蛋白2（UCP2）mRNA水平以及呼吸的决定因素（ATP合成、质子泄漏和非线粒体呼吸）。
肝脏灌注后，通过密度梯度离心继以逆流离心淘洗法纯化库普弗细胞。通过Northern印迹法测量UCP2 mRNA水平，通过极谱法测量呼吸参数。
在从甲状腺功能亢进（用三碘甲状腺原氨酸（T(3)）处理）大鼠分离的细胞中，T(3)处理对UCP2 mRNA水平的影响各不相同：在急性T(3)处理的大鼠中，其增加了一倍多（P<0.05），但在慢性（3周）T(3)处理后，仅比对照（甲状腺功能正常）水平高30%（无统计学意义）。在慢性甲状腺功能亢进大鼠肝脏的库普弗细胞中，我们观察到总呼吸速率增加，质子泄漏所占百分比增加，而ATP合成所占百分比相应降低（非线粒体呼吸所占百分比未观察到改变）。在急性甲状腺功能亢进大鼠中，尽管所有呼吸参数均有增加趋势，但未观察到任何显著差异。
这些数据表明UCP2在库普弗细胞中可能具有解偶联作用。T(3)通过增强UCP2的表达，可能在这些细胞的能量稳态中发挥作用。
