Article Title: Propofol inhibits stromatoxin-1-sensitive voltage-dependent K+ channels in pancreatic β-cells and enhances insulin secretion
Figure Lengend Snippet: Effect of propofol on voltage-dependent outward potassium currents in mouse MIN6 cells. Representative tracings of whole-cell currents obtained from a mouse MIN6 cell in the absence (A) or the presence of stromatoxin-1 (100 nM) (B), and propofol (50 µM) (C). The cell was held at −88 mV and stepped up for 0.4 s to potentials ranging between −88 and +52 mV in 10 mV steps. (D) Current–voltage (I–V) relationships of whole-cell currents in the steady state with varying concentrations of propofol (in µM). Propofol blocked the outward K + currents in a dose-dependent manner ( n = 6). (E) Semi-logarithmic plot of the current at +52 mV vs. concentration of propofol. The line is the best fit by the Hill equation. (F) The inhibitory constant (Ki) was indifferent between −8 and +52 mV. (G, H) MIN6 cells were exposed to strmatoxin-1 (0–100 nM) for 1 h with 2 mM and 20 mM glucose. (I) β-cells/islets were exposed to stromatoxin-1 (100 nM) for 1 h with 2 mM and 20 mM glucose. Insulin secretion was determined as described in ‘Materials and Methods’. Data are presented as mean ± SD ( n = 5). Differences between treatments were evaluated by one-way ANOVA followed by Dunnett’s test for multiple comparisons. * P
Article Snippet: Glibenclamide was obtained from Wako Pure Chemical Industries, Ltd. (Osaka, Japan), diazoxide from Abcam (Cambridge, MA, USA), and stromatoxin-1 from Alomone Labs Ltd. (Jerusalem, Israel).
Techniques: Concentration Assay