Frittitta L, Youngren J, Vigneri R, Maddux B A, Trischitta V, Goldfine I D
Istituto di Medicina Interna e Malattie Endocrine e Metaboliche, Università di Catania, Ospedale Garibaldi, Italy.
Diabetologia. 1996 Oct;39(10):1190-5. doi: 10.1007/BF02658505.
Insulin sensitivity varies widely in non-obese, non-diabetic subjects, and we have previously reported that in vivo insulin action correlates with in vitro insulin stimulated insulin receptor tyrosine-kinase activity in skeletal muscle. Plasma membrane glyco-protein PC-1 content is elevated in fibroblasts of insulin-resistant subjects, and expression of PC-1 cDNA in cultured cells reduces both insulin receptor tyrosine-kinase activity and the biological actions of insulin. In the present study we investigated non-obese, non-diabetic subjects and found a significant negative correlation between muscle PC-1 content and both in vivo insulin action as measured by the intravenous insulin tolerance test (r = -0.51, p = 0.035) and the sensitivity (ED50) of in vitro insulin stimulation of insulin receptor tyrosine-kinase activity (r = 0.66, p = 0.027). These studies indicate, therefore, that increased muscle PC-1 content is associated with reduced insulin action both in vivo and in vitro. Moreover, they suggest a possible role for PC-1 in regulating insulin receptor function in human skeletal muscle.
胰岛素敏感性在非肥胖、非糖尿病个体中差异很大，我们之前报道过，体内胰岛素作用与体外胰岛素刺激的骨骼肌胰岛素受体酪氨酸激酶活性相关。胰岛素抵抗个体的成纤维细胞中质膜糖蛋白PC-1含量升高，在培养细胞中PC-1 cDNA的表达降低了胰岛素受体酪氨酸激酶活性以及胰岛素的生物学作用。在本研究中，我们调查了非肥胖、非糖尿病个体，发现肌肉PC-1含量与通过静脉胰岛素耐量试验测量的体内胰岛素作用（r = -0.51，p = 0.035）以及体外胰岛素刺激胰岛素受体酪氨酸激酶活性的敏感性（ED50）之间存在显著负相关（r = 0.66，p = 0.027）。因此，这些研究表明，肌肉PC-1含量增加与体内和体外胰岛素作用降低有关。此外，它们提示PC-1在调节人类骨骼肌胰岛素受体功能中可能发挥作用。
