Adipose tissue triglyceride turnover, de novo lipogenesis, and cell proliferation in humans measured with 2H2O
Adipose tissue triglyceride turnover, de novo lipogenesis, and cell proliferation in humans measured with 2H2O
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DOI：
10.1152/ajpendo.00093.2003
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发表时间：
2004-04-01
影响因子：
5.1
通讯作者：
Hellerstein, MK
中科院分区：
文献类型：
--
作者：
Strawford, A;Antelo, F;Hellerstein, MK
脂肪组织成分(脂质和细胞)的周转和脂肪沉积的途径在人类中一直很难测量。在这里，我们应用(H2O)-H-2长期标记技术同时测量脂肪甘油三酯(TG)周转率、细胞(DNA)增殖和新生脂肪生成(DNL)。健康受试者饮用(H2O)-H-2(70ml/d)5~9wk。抽取皮下脂肪组织(臀部、大腿和腰部)。用气相色谱-质谱法测定了TG甘油(代表全源TG合成)、TG棕榈酸酯(代表DNL，通过质量同位素分布分析)和DNA(代表细胞增殖)中的氚掺入量。受试者对该方案耐受性良好，体内(H2O)-H-2浓集稳定。甘油三酯合成的平均分数为0.12(即12%)，5 wk后为0.03-0.32，9 wk(TG半衰期200-270天)为0.20(0.08-0.49)。停止(H2O)-H-2后5-8个月的标签衰减测量给出了类似的周转率估计。净脂肪分解(甘油三酯周转率)为50~60g/d。DNL对脂肪-甘油三酯的贡献在9wk后为0.04，相当于新沉积甘油三酯的20%。9wk(半衰期240~425天)后细胞增殖率为0.10~0.17。总而言之，受试者长期服用(H2O)-H-2可以测量脂肪组织成分的动态变化。所有元素的周转缓慢，DNL对新TG的贡献接近20%。
The turnover of adipose tissue components ( lipids and cells) and the pathways of adipose lipid deposition have been difficult to measure in humans. We apply here a (H2O)-H-2 long-term labeling technique for concurrent measurement of adipose-triglyceride (TG) turnover, cell ( DNA) proliferation, and de novo lipogenesis (DNL). Healthy subjects drank (H2O)-H-2 ( 70 ml/day) for 5 - 9 wk. Subcutaneous adipose tissue aspirates were taken ( gluteal, thigh, and flank depots). Deuterium incorporation into TG glycerol ( representing all-source TG synthesis), TG palmitate ( representing DNL, by mass isotopomer distribution analysis), and DNA ( representing cell proliferation) was measured by gas chromatography-mass spectrometry. Subjects tolerated the protocol well, and body (H2O)-H-2 enrichments were stable. Mean TG-glycerol fractional synthesis was 0.12 (i.e., 12%) with a range of 0.03-0.32 after 5 wk and 0.20 ( range 0.08 - 0.49) after 9 wk ( TG half-life 200 - 270 days). Label decay measurements 5 - 8 mo after discontinuing (H2O)-H-2 gave similar turnover estimates. Net lipolysis ( TG turnover) was 50 - 60 g/day. DNL contribution to adipose-TG was 0.04 after 9 wk, representing similar to 20% of newly deposited TG. Cell proliferation was 0.10 - 0.17 after 9 wk (half-life 240 - 425 days). In summary, long-term (H2O)-H-2 administration to human subjects allows measurement of the dynamics of adipose tissue components. Turnover of all elements is slow, and DNL contributes similar to 20% of new TG.