Kobayashi K, Tsumura Y, Ise H, Kagawa S, Matsuoka A
Endocrinol Jpn. 1977 Oct;24(5):451-6. doi: 10.1507/endocrj1954.24.451.
The sensitized effect of prestimulation with 16.7 mM glucose on insulin release with a slow-rise glucose stimulation from the perifused rat islets of Langerhans was studied, together with the kinetic analysis of insulin release, and the interrelationship between the prestimulation time and the maximal rate of insulin release. All dose-response relationships which were derived from the dynamics of insulin release from islets prestimulated over various time periods within 60 min, showed sigmoidal profiles. Kinetic analyses were performed with Lineweaver-Burk's and Hill's equations. The 30-min prestimulation significantly reduced Hill's constant (n) from 6.2 +/- 0.7 of the control to 3.7 +/- 0.6 (p less than 0.05) and also enhanced the logarithmic equilibrium constant (log K) from -5.4 +/- 0.6 mM-n to -3.7 +/- 0.6 mM-n (p less than 0.05). However, the Km value was almost the same as that of the control (7.3 +/- 0.5 mM). On the other hand, the 60-min prestimulation remarkably diminished the Km value and the maximal rate of insulin release to 5.3 +/- 0.4 mM (p less than 0.05) and 0.6 +/- 0.08 muU/ml/islet/min (p less than 0.005), respectively. The maximal rate of insulin release linearly increased in proportion to the prestimulation time within 30 min. In conclusion, these results suggested that there would be some regularity depending on the prestimulation time in the process of transmission of the insulin-releasing signal in the pancreatic B cell and the accumulation of insulin into the provisional pool such as the labile insulin.
研究了用16.7 mM葡萄糖预刺激对从大鼠胰岛灌流的胰岛在缓慢升高葡萄糖刺激下胰岛素释放的致敏作用，同时进行了胰岛素释放的动力学分析以及预刺激时间与胰岛素最大释放速率之间的相互关系。从在60分钟内不同时间段预刺激的胰岛释放胰岛素的动力学得出的所有剂量反应关系均呈S形曲线。用Lineweaver-Burk方程和Hill方程进行动力学分析。30分钟的预刺激显著降低了Hill常数（n），从对照的6.2±0.7降至3.7±0.6（p＜0.05），并使对数平衡常数（log K）从-5.4±0.6 mM-n提高到-3.7±0.6 mM-n（p＜0.05）。然而，Km值与对照几乎相同（7.3±0.5 mM）。另一方面，60分钟的预刺激显著降低了Km值和胰岛素最大释放速率，分别降至5.3±0.4 mM（p＜0.05）和0.6±0.08 μU/ml/胰岛/分钟（p＜0.005）。在30分钟内，胰岛素最大释放速率与预刺激时间成线性比例增加。总之，这些结果表明，在胰腺B细胞中胰岛素释放信号的传递过程以及胰岛素向诸如不稳定胰岛素等临时池的积累过程中，根据预刺激时间会存在一些规律。
