Tisular, Facultad de Medicina, Universidad Nacional Autónoma de México, Av. Universidad 3000, Circuito Interior S/N, Universidad Nacional Autónoma de México, C.U., CDMXLaboratorio de sinapsis eléctricas. Departamento de Biología Celular y , México.
Human Genetics Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile.
Islets. 2022 Dec 31;14(1):149-163. doi: 10.1080/19382014.2022.2091886.
Biotin supplemented diet (BSD) is known to enhance β-cell replication and insulin secretion in mice. Here, we first describe BSD impact on the islet β-cell membrane potential (Vm) and glucose-induced electrical activity. BALB/c female mice (n ≥ 20) were fed for nine weeks after weaning with a control diet (CD) or a BSD (100X). In both groups, islet area was compared in pancreatic sections incubated with anti-insulin and anti-glucagon antibodies; Vm was recorded in micro dissected islet β-cells during perfusion with saline solutions containing 2.8, 5.0, 7.5-, or 11.0 mM glucose. BSD increased the islet and β-cell area compared with CD. In islet β-cells of the BSD group, a larger ΔVm/Δ[glucose] was found at sub-stimulatory glucose concentrations and the threshold glucose concentration for generation of action potentials (APs) was increased by 1.23 mM. Moreover, at 11.0 mM glucose, a significant decrease was found in AP amplitude, frequency, ascending and descending slopes as well as in the calculated net charge influx and efflux of islet β-cells from BSD compared to the CD group, without changes in slow Vm oscillation parameters. A pharmacological dose of biotin in mice increases islet insulin cell mass, shifts islet β-cell intracellular electrical activity dose response curve toward higher glucose concentrations, very likely by increasing K conductance, and decreases voltage gated Ca and K conductance at stimulatory glucose concentrations.
生物素补充饮食（BSD）已知可增强小鼠胰岛β细胞的复制和胰岛素分泌。在这里，我们首先描述 BSD 对胰岛β细胞膜电位（Vm）和葡萄糖诱导的电活性的影响。断奶后，雌性 BALB/c 小鼠（n≥20）用对照饮食（CD）或 BSD（100X）喂养九周。在两组中，用抗胰岛素和抗胰高血糖素抗体孵育胰腺切片，比较胰岛面积；在含有 2.8、5.0、7.5 或 11.0 mM 葡萄糖的盐溶液灌流期间，记录微分离的胰岛β细胞中的 Vm。与 CD 相比，BSD 增加了胰岛和β细胞面积。在 BSD 组的胰岛β细胞中，在亚刺激葡萄糖浓度下发现更大的 ΔVm/Δ[glucose]，并且产生动作电位（AP）的阈值葡萄糖浓度增加了 1.23 mM。此外，在 11.0 mM 葡萄糖下，与 CD 组相比，BSD 组胰岛β细胞的 AP 幅度、频率、上升和下降斜率以及计算的净电荷流入和流出显著降低，而缓慢 Vm 振荡参数没有变化。在小鼠中，生物素的药理剂量增加胰岛胰岛素细胞质量，将胰岛β细胞细胞内电活动剂量反应曲线向更高的葡萄糖浓度转移，很可能通过增加 K 电导来实现，并降低刺激葡萄糖浓度下的电压门控 Ca 和 K 电导。
