Clore J N, Li J, Gill R, Gupta S, Spencer R, Azzam A, Zuelzer W, Rizzo W B, Blackard W G
Division of Endocrinology and Metabolism, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 23298, USA.
Am J Physiol. 1998 Oct;275(4):E665-70. doi: 10.1152/ajpendo.1998.275.4.E665.
The fatty acid composition of skeletal muscle membrane phospholipids (PL) is known to influence insulin responsiveness in humans. However, the contribution of the major PL of the outer (phosphatidylcholine, PC) and inner (phosphatidylethanolamine, PE) layers of the sarcolemma to insulin sensitivity is not known. Fatty acid composition of PC and PE from biopsies of vastus lateralis from 27 normal men and women were correlated with insulin sensitivity determined by the hyperinsulinemic euglycemic clamp technique at insulin infusion rates of 0.4, 1.0, and 10.0 mU . kg-1 . min-1. Significant variation in the half-maximal insulin concentration (ED50) was observed in the normal volunteers (range 24.0-146.0 microU/ml), which correlated directly with fasting plasma insulin (r = 0.75, P < 0.0001). ED50 was inversely correlated with the degree of membrane unsaturation (C20-C22 polyunsaturated fatty acids; r = 0. 58, P < 0.01) and directly correlated with fatty acid elongation (ratio of 16:0 to 18:0, r = 0.45, P < 0.05) in PC. However, no relationship between fatty acid composition and insulin sensitivity was observed in PE (NS). These studies suggest that the fatty acid composition of PC may be of particular importance in the relationship between fatty acids and insulin sensitivity in normal humans.
众所周知，骨骼肌膜磷脂（PL）的脂肪酸组成会影响人体的胰岛素反应性。然而，肌膜外层（磷脂酰胆碱，PC）和内层（磷脂酰乙醇胺，PE）的主要磷脂对胰岛素敏感性的贡献尚不清楚。对27名正常男性和女性的股外侧肌活检样本中的PC和PE的脂肪酸组成，与通过高胰岛素正常血糖钳夹技术在胰岛素输注速率为0.4、1.0和10.0 mU·kg⁻¹·min⁻¹时测定的胰岛素敏感性进行了相关性分析。在正常志愿者中观察到半数最大胰岛素浓度（ED50）存在显著差异（范围为24.0 - 146.0微单位/毫升），其与空腹血浆胰岛素直接相关（r = 0.75，P < 0.0001）。ED50与膜不饱和程度（C20 - C22多不饱和脂肪酸；r = 0.58，P < 0.01）呈负相关，与PC中的脂肪酸延长（16:0与18:0的比值，r = 0.45，P < 0.05）呈正相关。然而，在PE中未观察到脂肪酸组成与胰岛素敏感性之间的关系（无显著性差异）。这些研究表明，在正常人体内，PC的脂肪酸组成在脂肪酸与胰岛素敏感性之间的关系中可能具有特别重要的意义。
