Meyer C, Nadkarni V, Stumvoll M, Gerich J
Department of Medicine, University of Rochester, School of Medicine, New York 14642, USA.
Am J Physiol. 1997 Sep;273(3 Pt 1):E650-4. doi: 10.1152/ajpendo.1997.273.3.E650.
To determine the relationship between free fatty acids (FFA) and glucose uptake by the human kidney, 12 postabsorptive normal volunteers underwent renal vein catheterization and were infused to isotopic steady state with [6-3H]glucose and [9,10-3H]palmitate. Arterial and renal vein palmitate specific activities were not significantly different (3,533 +/- 219 vs. 3,549 +/- 220 dpm/mumol, P = 0.64). Palmitate renal fractional extraction and uptake determined isotopically (7.2 +/- 1.1% and 9.1 +/- 1.4 mumol/min) were not significantly different from those calculated by net balance measurements (8.3 +/- 1.2% and 9.7 +/- 1.2 mumol/min, P > 0.07 and P > 0.7, respectively). Renal palmitate uptake accounted for 8.7 +/- 1.3% of its systemic turnover. Renal linoleate and oleate fractional extraction calculated by net balance measurements (8.0 +/- 0.9 and 7.7 +/- 1.2%, respectively) were not significantly different from each other and that of palmitate (all P > 0.7). Renal uptake of palmitate, linoleate (7.9 +/- 1.0 mumol/min), and oleate (10.9 +/- 2.0 mumol/min) were all directly proportional to their arterial concentrations (r = 0.70, 0.68, and 0.63, respectively, all P < 0.025). Renal glucose uptake (93 +/- 10 mumol/min) accounted for 12.6 +/- 1.5% of its systemic turnover and was inversely related to the sum of palmitate, linoleate, and oleate uptake (r = -0.74, P < 0.01). These data indicate that in postabsorptive humans: 1) the kidney is an important site of FFA and glucose disposal, 2) a renal glucose-fatty acid cycle may exist, and 3) there appears to be little or no release into the circulation of stored renal FFA.
为了确定游离脂肪酸（FFA）与人体肾脏葡萄糖摄取之间的关系，12名吸收后状态正常的志愿者接受了肾静脉插管，并以[6-³H]葡萄糖和[9,10-³H]棕榈酸酯输注至同位素稳态。动脉血和肾静脉血中棕榈酸酯的比活性无显著差异（3533±219与3549±220 dpm/μmol，P = 0.64）。通过同位素测定的棕榈酸酯肾脏分数提取率和摄取量（7.2±1.1%和9.1±1.4 μmol/min）与通过净平衡测量计算的值（8.3±1.2%和9.7±1.2 μmol/min）无显著差异（分别为P>0.07和P>0.7）。肾脏对棕榈酸酯的摄取占其全身周转率的8.7±1.3%。通过净平衡测量计算的肾脏亚油酸酯和油酸酯分数提取率（分别为8.0±0.9和7.7±1.2%）彼此之间以及与棕榈酸酯的分数提取率均无显著差异（所有P>0.7）。肾脏对棕榈酸酯、亚油酸酯（7.9±1.0 μmol/min）和油酸酯（10.9±2.0 μmol/min）的摄取均与其动脉血浓度成正比（r分别为0.70、0.68和0.63，所有P<0.025）。肾脏葡萄糖摄取量（93±10 μmol/min）占其全身周转率的12.6±1.5%，且与棕榈酸酯、亚油酸酯和油酸酯摄取量之和呈负相关（r = -0.74，P<0.01）。这些数据表明，在吸收后状态的人体中：1）肾脏是游离脂肪酸和葡萄糖代谢的重要场所；2）可能存在肾脏葡萄糖-脂肪酸循环；3）储存的肾脏游离脂肪酸似乎很少或没有释放到循环中。
