Jehle P M, Jehle D, Fussgänger R D, Adler G
Department of Internal Medicine I, University of Ulm, Germany.
Exp Clin Endocrinol Diabetes. 1995;103 Suppl 2:31-6. doi: 10.1055/s-0029-1211391.
Glucagon-like peptide-1 (GLP-1) is the major incretin hormone from the distal small intestine which stimulates basal and glucose-induced insulin secretion. Using the rat insulinoma cell line RINm5F (Gazdar et al. 1980) we investigated the effects of GLP-1 on insulin secretion, insulin content, and insulin receptor binding. During a 1 hour incubation, GLP-1 [1 nM] stimulated insulin secretion 2-fold (p < 0.01 vs controls). Incubating RINm5F for 24 h with GLP-1 [1 nM], a 1.6-fold higher cellular insulin content was observed (p < 0.01 vs controls). Moreover, GLP-1 induced a 2-fold higher capacity and a 15-fold higher affinity of 125I-insulin binding on the cell surface (p < 0.01 vs controls). Glucagon, known as a potent stimulator of insulin secretion, yielded a similar effect only in 1,000-fold higher concentrations, whereas the intracellular insulin content as well as insulin receptor binding was not increased. Taken together, in RINm5F insulinoma cells GLP-1 potently stimulates insulin secretion and insulin content, and improves insulin receptor binding.
胰高血糖素样肽-1（GLP-1）是来自小肠远端的主要肠促胰岛素激素，可刺激基础胰岛素分泌以及葡萄糖诱导的胰岛素分泌。我们使用大鼠胰岛素瘤细胞系RINm5F（Gazdar等人，1980年）研究了GLP-1对胰岛素分泌、胰岛素含量和胰岛素受体结合的影响。在1小时的孵育过程中，GLP-1[1 nM]刺激胰岛素分泌增加了2倍（与对照组相比，p<0.01）。将RINm5F与GLP-1[1 nM]孵育24小时后，观察到细胞内胰岛素含量高出1.6倍（与对照组相比，p<0.01）。此外，GLP-1使细胞表面125I-胰岛素结合的能力提高了2倍，亲和力提高了15倍（与对照组相比，p<0.01）。胰高血糖素作为一种已知的胰岛素分泌强效刺激剂，仅在浓度高出1000倍时才产生类似效果，而细胞内胰岛素含量以及胰岛素受体结合并未增加。综上所述，在RINm5F胰岛素瘤细胞中，GLP-1可有效刺激胰岛素分泌和胰岛素含量，并改善胰岛素受体结合。
