Long C A, Patton S
J Dairy Sci. 1978 Oct;61(10):1392-9. doi: 10.3168/jds.S0022-0302(78)83740-0.
The lipogenic system of fresh goat milk was used to investigate the relationship of lipid synthesis to formation of fat droplets. The skim milk phase was incubated with [1-carbon-14] palmitate and incorporation of activity into the glycerolipids was assayed. In two representative experiments, 44 and 56% of the label was incorporated into the lipids. Most of this activity (78 to 84%) was in triglycerides. Of 12 and 10% activity in the phospholipids, about 60% was contained in phosphatidylcholine with substantially smaller amounts in the other phospholipids. The synthesis of triglyceride and phosphatidylcholine was further investigated in relation to distribution of labeled lipids in a cream layer and a sedimenting fluff (membrane) fraction derived by centrifuging the skim milks following incubation. The correlation coefficient for the amounts of activity in phosphatidylcholine and triglyceride in the cream layer was .97. The data are consistent with synthesis of phosphatidylcholine and triglyceride to meet the requirements of surface and volume expansion, respectively, in formation of fat droplets. Our findings suggest the interesting working hypothesis that phosphatidylcholine synthesis regulates development of fat droplets.
利用新鲜山羊奶的脂肪生成系统来研究脂质合成与脂肪球形成之间的关系。将脱脂乳相用[1-碳-14]棕榈酸进行孵育，并测定活性物质掺入甘油脂质中的情况。在两个代表性实验中，44%和56%的标记物掺入了脂质中。其中大部分活性（78%至84%）存在于甘油三酯中。在磷脂中的活性分别为12%和10%，其中约60%存在于磷脂酰胆碱中，其他磷脂中的含量则少得多。进一步研究了甘油三酯和磷脂酰胆碱的合成与孵育后脱脂乳经离心得到的乳脂层和沉淀绒毛（膜）部分中标记脂质分布的关系。乳脂层中磷脂酰胆碱和甘油三酯的活性量的相关系数为0.97。这些数据与磷脂酰胆碱和甘油三酯的合成分别满足脂肪球形成过程中表面和体积扩张的需求相一致。我们的研究结果提出了一个有趣的工作假设，即磷脂酰胆碱的合成调节脂肪球的发育。
