Effect of Propofol, an Intravenous Anesthetic Agent, on $K_{ATP}$ Channels of Pancreatic ${\beta}-cells$ in Rats

  • Park, Eun-Jee (Department of Anesthesiology, Keimyung University School of Medicine) ;
  • Song, Dae-Kyu (Department of Physiology, Keimyung University School of medicine) ;
  • Cheun, Jae-Kyu (Department of Anesthesiology, Keimyung University School of Medicine) ;
  • Bae, Jung-In (Department of Anesthesiology, Keimyung University School of Medicine) ;
  • Ho, Won-Kyung (Department of Physiology, Seoul National University College of Midicine) ;
  • Earm, Yung-E (Department of Physiology, Seoul National University College of Midicine)
  • 발행 : 2000.02.21

초록

ATP-sensitive potassium channels ($K_{ATP}$ channels) play an important role in insulin secretion from pancreatic beta cells. We have investigated the effect of propofol on $K_{ATP}$ 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 $K_{ATP}$ channel activities in a dose-dependent manner. The half-maximal inhibition dose (ED50) was $48.6{\pm}8.4\;{\mu}M$ and the Hill coefficient was $0.73{\pm}0.11.$ Single channel conductance calculated from the slope of the relationship between single channel current and pipette potential $(+20{\sim}+100\;mV)$ was not significantly altered by propofol $(control:\;60.0{\pm}2.7\;pS,\;0.1\;mM\;propofol:\;58.7{\pm}3.5\;pS).$ However, mean closed time was surely increased. Above results indicate that propofol blocks the $K_{ATP}$ 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.

키워드