Korean J Anesthesiol.  2007 Jan;52(1):67-71. 10.4097/kjae.2007.52.1.67.

The Effect of Midazolam on Outward K+ Channel Currents in Rabbit Cerebral Arterial Smooth Muscle Cells

• Shin YC
• Shim JH
• Jeon WJ
• Cho SY
• Shin WJ
• Kim KH
• Yeom JH

• KMID: 2236645
• DOI: http://doi.org/10.4097/kjae.2007.52.1.67

Abstract

BACKGROUND
Midazolam has a direct relaxing effect on vascular smooth muscle, but the mechanisms that this agent produces muscle relaxation are not fully understood. The current study was performed to identify the effects of the midazolam on K+ channels current in rabbit cerebral arterial smooth muscle cells.
METHODS
Whole cell patch-clamp recording technique was used to evaluate the effects of midazolam (0.1 to 100micrometer) on outward K+ channel currents in dispersed rabbit cerebral arterial smooth muscle cells.
RESULTS
Outward K+ currents of rabbit cerebral artery smooth muscle cells were voltage-dependent. Midazolam (10, 100micrometer) tested significantly inhibited outward K+ currents in a dose-dependent manner and half-blocking concentration (IC50) was 15.94micrometer at 60 mV.
CONCLUSIONS
Midazolam inhibit outward K+ currents of rabbit cerebral arterial smooth muscle cells. Further study will be needed to determine the effect of midazolam on calcium channel current because it is unclear if the inhibitory effect of midazolam on outward K+current induces vasoconstriction.

Keyword

midazolam; outward K+ currents; rabbit cerebral arterial smooth muscle cell

MeSH Terms

Calcium Channels
Cerebral Arteries
Midazolam*
Muscle Relaxation
Muscle, Smooth*
Muscle, Smooth, Vascular
Myocytes, Smooth Muscle*
Vasoconstriction
Calcium Channels
Midazolam