Role of unsaturated fatty acids in brown adipose tissue function - with special reference to docosahexaenoic acid.

为了阐明膜磷脂n-3多不饱和脂肪酸（DHA）的作用，研究了不同条件下大鼠棕色脂肪组织（BAT） DHA的变化。(1) DHA和花生四烯酸（AA）在新生儿期和BAT产热期均高于成虫。(2)添加dha的饲料增加了BAT- dha，降低了AA，导致BAT体外产热作用不变或降低。(3)缺乏dha的饮食降低了BAT- dha，但不影响不含BAT的AA体外产热。(4) DHA加aa增加了BAT中两种脂肪酸的含量，但对BAT的体外产热没有影响。解偶联蛋白1mrna表达增加。(5)长期给药一氧化氮合酶L-NAME不改变BAT- dha，但由于细胞活性降低而使BAT体外产热能力降低。(6)热驯化或禁食降低了BAT-DHA和体外产热，两者之间存在相关性。(7)甲巯咪唑诱导的甲状腺功能减退症使DHA和AA均减少，导致BAT体外产热下降。三碘甲状腺原氨酸诱导的甲状腺机能亢进增加了因增生引起的BAT体外产热，但DHA没有改变。(8)新生儿期至幼龄期的低饲养温度影响了长期改善的BAT体外产热和后期的全身非寒颤产热。这些结果提示DHA是BAT产热功能的控制因素之一。

In an attempt to elucidate a role of membrane phospholipid n-3 polyunsaturated fatty acid (DHA) , the changes in DHA of rat brown adipose tissue (BAT) were studied under various conditions. (1) DHA and arachidonic acid (AA) were higher during neonatal period with higher BAT thermogenesis than in the adults. (2) DHA-supplemented diet increased BAT-DHA but decreased AA, resulting in the unchanged or decreased BAT in vitro thermogenesis. (3) DHA-deficient diet decreased BAT-DHA but not AA without BAT in vitro thermogenesis. (4) DHA plus AA-supplemented diet increased both fatty acids in BAT but did not change BAT in vitro thermogenesis. However, uncoupling protein 1 mRNA expression increased. (5) Chronic administration of nitric oxide synthase L-NAME did not change BAT-DHA, but decreased BAT in vitro thermogenesis due to decreased cellularity. (6) Heat acclimation or fasting decreased BAT-DHA and in vitro thermogenesis with correlation between these both parameters. (7) Methimazole-induced hypothyroidism decrease both DHA and AA, causing the decrease in BAT in vitro thermogenesis. Triiodothyronine-induced hyperthyroidism increased BAT in vitro thermogenesis due to hyperplasia without the changes of DHA. (8) Low rearing temperature during the neonatal to young period effected the long-lasting improved BAT in vitro thermogenesis as well as systemic nonshivering thermogenesis in later life. These findings suggest that DHA subserves as one of controlling factors of BAT thermogenic function.