Oberkotter L V, Rasmussen K M
Division of Cell and Molecular Biology, Florida Institute of Technology, Melbourne 32901.
J Nutr. 1992 Mar;122(3):435-41. doi: 10.1093/jn/122.3.435.
To examine the joint effects of lactation and dietary restriction on thyroid function, we studied chronically food-restricted rat dams at conception and dams and their pups during the nursing period compared with controls that had free access to food. As expected, both dietary restriction [plasma thyroxine and 3,3',5-triiodothyronine (T3) values were lower and reverse T3 (rT3) values were higher in food-restricted than in control rats] and stage of lactation (T3 values decreased in both groups) had independent effects on maternal thyroid function. There also were interactive effects: rT3 values decreased during lactation among the food-restricted dams but remained constant among controls. Maternal dietary restriction also did not have a consistent effect on pup thyroid function during the nursing period: in offspring of food-restricted compared with control dams, plasma thyroxine values were lower only at d 14, T3 values were lower at d 7-21, and rT3 values were higher from birth to d 14. These data demonstrate that dietary restriction and lactation have synergistic negative effects on thyroid status in lactating rats and their pups and that thyroid hormone ontogeny is retarded in the offspring of food-restricted rats. These hormonal effects may contribute to the impaired milk production of food-restricted rats and to altered growth characteristics of their offspring.
为了研究哺乳期和饮食限制对甲状腺功能的联合影响，我们对受孕时长期食物受限的大鼠母鼠以及哺乳期的母鼠及其幼崽进行了研究，并将其与可自由获取食物的对照组进行比较。正如预期的那样，饮食限制（食物受限大鼠的血浆甲状腺素和3,3',5-三碘甲状腺原氨酸（T3）值较低，而反式T3（rT3）值较高）和哺乳期阶段（两组的T3值均下降）对母体甲状腺功能均有独立影响。此外还存在交互作用：食物受限母鼠在哺乳期rT3值下降，而对照组则保持不变。母体饮食限制在哺乳期对幼崽甲状腺功能也没有一致的影响：与对照母鼠的后代相比，食物受限母鼠的后代仅在第14天时血浆甲状腺素值较低，第7至21天时T3值较低，从出生到第14天时rT3值较高。这些数据表明，饮食限制和哺乳期对泌乳大鼠及其幼崽的甲状腺状态具有协同负面影响，并且食物受限大鼠后代的甲状腺激素个体发育受到阻碍。这些激素效应可能导致食物受限大鼠的产奶量受损及其后代生长特征改变。
