Leclercq-Meyer V, Giroix M H, Sener A, Marchand J, Malaisse W J
Laboratory of Experimental Medicine, Brussels Free University, Belgium.
Int J Pancreatol. 1988 Jan-Feb;3(1):17-31. doi: 10.1007/BF02788220.
Perifused tumoral insulin-producing cells, of the RINm5F line, display a high basal insulin output relative to their hormonal content. D-Glucose (2.8 or 16.7 mmol/l) causes a modest and monophasic increase in insulin output. The secretory response to D-glucose (1.4 to 16.7 mmol/l) is enhanced by forskolin, which exerts little effect in the absence of exogenous nutrient. L-Leucine (10.0 mmol/l) also stimulates insulin release from the perifused cells. The secretory response to these nutrient secretagogues in much less marked, however, than that evoked, in the absence of Ca2+, by the association of Ba2+ and theophylline. It is concluded that the dynamics of insulin release by the tumoral cells, when compared to that of normal islet cells, are characterized by several anomalies, including a high basal ratio between secretion and content, a low threshold (less than or equal to 1.4 mmol/l) in the secretory response to D-glucose, and a lesser responsiveness to nutrient than nonnutrient secretagogues.
用RINm5F细胞系建立的灌流肿瘤胰岛素分泌细胞，相对于其激素含量，具有较高的基础胰岛素分泌量。D-葡萄糖（2.8或16.7 mmol/L）可引起胰岛素分泌适度的单相增加。福斯可林可增强对D-葡萄糖（1.4至16.7 mmol/L）的分泌反应，在无外源营养物时其作用甚微。L-亮氨酸（10.0 mmol/L）也可刺激灌流细胞释放胰岛素。然而，这些营养性促分泌剂引起的分泌反应，远不如在无Ca2+时Ba2+与茶碱联合引起的分泌反应明显。结论是，与正常胰岛细胞相比，肿瘤细胞胰岛素释放的动力学具有若干异常特征，包括分泌与含量之间的基础比率较高、对D-葡萄糖分泌反应的阈值较低（小于或等于1.4 mmol/L）以及对营养性促分泌剂的反应性低于非营养性促分泌剂。
