Aceves C, Escobar C, Rojas-Huidobro R, Vázquez-Martínez O, Martínez-Merlos T, Aguilar-Roblero R, Díaz-Muñoz M
Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, México.
J Endocrinol. 2003 Oct;179(1):91-6. doi: 10.1677/joe.0.1790091.
Restricted feeding schedules (RFSs) produce a behavioral activation known as anticipatory activity, which is a manifestation of a food-entrained oscillator (FEO). The liver could be playing a role in the physiology of FEO. Here we demonstrate that the activity of liver selenoenzyme deiodinase type 1 (D1), which transforms thyroxine into triiodothyronine (T3), decreases before food access and increases after food presentation in RFSs. These changes in D1 activity were not due to variations in D1 mRNA. In contrast, a 24 h fast promoted a decrease in both D1 activity and mRNA content. The adjustment in hepatic D1 activity was accompanied by a similar modification in T3-dependent malic enzyme, suggesting that the local generation of T3 has physiological implications in the liver. These results support the notion that the physiological state of rats under RFSs is unique and distinct from rats fed freely or fasted for 24 h. Data also suggest a possible role of hepatic D1 enzyme in coordinating the homeorhetic state of the liver when this organ participates in FEO expression.
限制进食时间表（RFSs）会产生一种被称为预期活动的行为激活，这是食物夹带振荡器（FEO）的一种表现。肝脏可能在FEO的生理学中发挥作用。在此，我们证明，在RFSs中，将甲状腺素转化为三碘甲状腺原氨酸（T3）的肝脏硒酶1型脱碘酶（D1）的活性在进食前降低，在进食后增加。D1活性的这些变化并非由于D1 mRNA的变化。相反，24小时禁食促进了D1活性和mRNA含量的降低。肝脏D1活性的调节伴随着T3依赖性苹果酸酶的类似变化，这表明肝脏中T3的局部生成具有生理学意义。这些结果支持了这样一种观点，即处于RFSs状态下的大鼠的生理状态是独特的，与自由进食或禁食24小时的大鼠不同。数据还表明，当肝脏参与FEO表达时，肝脏D1酶在协调肝脏的同态调节状态方面可能发挥作用。
