Differential Effects of Etomidate and Midazolam on Vascular Adenosine Triphosphate–sensitive Potassium Channels

Abstract

Clinical concentrations of etomidate, but not midazolam, inhibit the KATP channel activity in vascular smooth muscle cells. The inhibition is presumably through its effects on the Kir6.0 subunit, but not on the SUR subunit, with the binding site different from adenosine triphosphate at the amino acid level.

Midazolam’s Effects on Delayed-Rectifier K+ Current and Intermediate-Conductance Ca2+-Activated K+ Channel in Jurkat T-lymphocytes

“…A previous report by Nakamura et al (2007) showed that MDZ could suppress vascular ATP-sensitive K + (K ATP ) channels. In our study, the internal solution used for whole-cell current recordings contained ATP at a concentration of 3 mM.…”

“…Neither diazoxide (30 µM) nor pinacidil (30 µM), which are activators of K ATP channels, reversed MDZinduced inhibition of I K(DR) (data not shown). Therefore, the observed effect of MDZ on inhibition of I K(DR) in Jurkat T-lymphocytes is unlikely to be mediated through its blockade of either K ATP channels or large-conductance Ca 2+ -activated K + channels [12,13].…”

“…Earlier reports showed that MDZ could be a direct regulator of ion channels, especially K + channels, and that these actions are thought to have pharmacological, toxicological or immunological implications [12][13][14][15][16]. In particular, K V 1.3 and Kv1.5-encoded currents, which exhibit unique gating properties and voltage dependency, largely constitute the delayed-rectifier K + currents (I K(DR ) in immune cells [3,[16][17][18].…”

Intraoperative Transesophageal Echocardiography Evaluation of Tricuspid Valve Re-repair for Ebstein’s Anomaly

“…Based on the results from the preoperative TTE, which showed sufficient size and mobility of the anterior leaflet, we determined that TV repair was suitable for this patient. Although several reports have mentioned the importance of intraoperative TEE in the evaluation of TV and RV function, there have been no reports describing actual measurements of intraoperative TEE and postoperative follow-up for TV repair in cases of Ebstein's anomaly [7][8][9].…”