Effect of Propofol, an Intravenous Anesthetic Agent, on K<SUB>ATP</SUB> Channels of Pancreatic β-cells in Rats

Effect of Propofol, an Intravenous Anesthetic Agent, on K<SUB>ATP</SUB> Channels of Pancreatic β-cells in Rats

<P> ATP-sensitive potassium channels (K<SUB>ATP</SUB> channels) play an important role in insulin secretion from pancreatic beta cells. We have investigated the effect of propofol on K<SUB>ATP</SUB> channels in cultured single pancreatic beta cells of rats. Channel activity was recorded from membrane patches using the patch-clamp technique. In the inside-out configuration bath-applied propofol inhibited the K<SUB>ATP</SUB> channel activities in a dose-dependent manner. The half-maximal inhibition dose (ED50) was 48.6&#8273;8.4μM and the Hill coefficient was 0.73&#8273;0.11. Single channel conductance calculated from the slope of the relationship between single channel current and pipette potential (&#8290;20∼&#8290;100 mV) was not significantly altered by propofol (control: 60.0&#8273;2.7 pS, 0.1 mM propofol: 58.7&#8273;3.5 pS). However, mean closed time was surely increased. Above results indicate that propofol blocks the K<SUB>ATP</SUB> channels in the pancreatic beta cells in the range of its blood concentrations during anesthesia, suggesting a possible effect on insulin secretion and blood glucose level.