Effects of Prostaglandin $F_{2{\alpha}}$ on Membrane Potentials and $K^+$ Currents in Rabbit Middle Cerebral Arterial Cells

  • Kim, Na-Ri (Department of Physiology and Biophysics, College of Medicine, Inje University) ;
  • Han, Jin (Department of Physiology and Biophysics, College of Medicine, Inje University) ;
  • Kim, Won-Gue (Department of Physiology and Biophysics, College of Medicine, Inje University) ;
  • Kim, Eui-Yong (Department of Physiology and Biophysics, College of Medicine, Inje University)
  • 발행 : 2000.08.21

초록

The purpose of our investigation was to examine the effects of prostaglandin $F_{2{\alpha}}\;(PGF_{2{\alpha}})$ on membrane potentials, $Ca^{2+}-activated\;K^+\;(K_{Ca})$ channels, and delayed rectifier $K^+(K_V)$ channels using the patch-clamp technique in single rabbit middle cerebral arterial smooth muscle cells. $PGF_{2{\alpha}}$ significantly hyperpolarized membrane potentials and increased outward whole-cell K currents. $PGF_{2{\alpha}}$ increased open-state probability of $K_{Ca}$ channels without the change of the open and closed kinetics. $PGF_{2{\alpha}}$ increased the amplitudes of $K_V$ currents with a leftward shift of activation and inactivation curves and a decrease of activation time constant. Our results suggest that the activation of $K_{Ca}$ and $K_V$ channels, at least in part, may lead to attenuate or counteract vasoconstriction by $PGF_{2{\alpha}}$ in middle cerebral artery.

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