Lang C A, Davis R A
Atherosclerosis and Hepatobiliary Research Center, University of Colorado Health Sciences Center, Denver 80262.
J Lipid Res. 1990 Nov;31(11):2079-86.
We determined the effect of the two major fish oil fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on VLDL assembly and secretion by cultured rat hepatocytes. The incorporation of [3H]glycerol into total triglyceride (cell plus media) was stimulated eight-fold when hepatocytes were incubated for 2 h with 1 mM EPA, DHA, or oleic acid (OA), suggesting that fish oil fatty acids stimulate hepatic triglyceride synthesis to an extent similar to OA. In contrast, mass quantitation of secreted triglyceride showed impaired triglyceride secretion with EPA and DHA compared to OA. During a 42-h time course, cells stimulated with EPA and DHA progressively accumulated triglyceride compared to cells stimulated with OA. To determine whether fish oil fatty acids impair very low density lipoprotein (VLDL) secretion, cells were labeled with [35S]methionine and the secretion of de novo synthesized apoB was measured. Compared to OA, EPA and DHA significantly impaired the secretion of both molecular weight forms of apoB. The cellular content of apoB was not altered by any of the fatty acids. The concordant decrease in the secretion of both triglyceride and apoB suggests that fish oil fatty acids impair VLDL assembly and/or secretion.
我们测定了两种主要的鱼油脂肪酸，即二十碳五烯酸（EPA）和二十二碳六烯酸（DHA），对培养的大鼠肝细胞极低密度脂蛋白（VLDL）组装和分泌的影响。当肝细胞与1 mM EPA、DHA或油酸（OA）孵育2小时时，[3H]甘油掺入总甘油三酯（细胞加培养基）的量增加了8倍，这表明鱼油脂肪酸刺激肝脏甘油三酯合成的程度与OA相似。相比之下，与OA相比，分泌甘油三酯的质量定量显示EPA和DHA存在甘油三酯分泌受损的情况。在42小时的时间进程中，与用OA刺激的细胞相比，用EPA和DHA刺激的细胞逐渐积累甘油三酯。为了确定鱼油脂肪酸是否会损害极低密度脂蛋白（VLDL）的分泌，用[35S]甲硫氨酸标记细胞并测量新生合成载脂蛋白B的分泌。与OA相比，EPA和DHA显著损害了两种分子量形式载脂蛋白B的分泌。任何一种脂肪酸均未改变载脂蛋白B的细胞含量。甘油三酯和载脂蛋白B分泌的一致减少表明鱼油脂肪酸损害了VLDL的组装和/或分泌。
