Gillis K D, Misler S
Department of Medicine (Jewish Hospital), Washington University, St. Louis, MO 63110.
Pflugers Arch. 1992 Jan;420(1):121-3. doi: 10.1007/BF00378654.
We have measured changes in membrane capacitance (delta Cm) in pancreatic B cells as a single cell assay of insulin secretion. Evidence that depolarization evoked delta Cm reflects exocytosis includes it's voltage, temperature and Ca2+ o dependence. Decreases in Cm, presumably reflecting endocytosis, occur on a variable time scale. Two features that make B cells unique among excitable cells are the large magnitude of delta Cm, when normalized to Ca2+ current, and the rapid "fatigue" of the response for even minimal stimulation, perhaps due to the depletion of a readily releasable pool of vesicles.
我们已测量了胰腺β细胞的膜电容变化（ΔCm），以此作为胰岛素分泌的单细胞检测方法。去极化诱发的ΔCm反映胞吐作用的证据包括其电压、温度和细胞外Ca²⁺依赖性。膜电容的降低可能反映内吞作用，其发生时间尺度不一。β细胞在可兴奋细胞中独有的两个特征是，当以Ca²⁺电流进行归一化时，ΔCm的幅度很大，以及即使是最小刺激，反应也会迅速“疲劳”，这可能是由于易于释放的囊泡池耗尽所致。
