English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

BACKGROUND Several recent studies suggest that activation of ATP-dependent potassium (K(ATP)) channels in the myocardium plays an important cardioprotective role during ischemia. The present study was undertaken to examine further the role of this ion channel in vivo in a model of "stunned" myocardium. METHODS AND RESULTS Barbital-anesthetized dogs were subjected to 15 minutes of left anterior descending (LAD) coronary artery occlusion followed by 3 hours of reperfusion. Regional myocardial blood flow was measured by radioactive microspheres and segment function by sonomicrometry. Intravenous administration of the potassium channel opener aprikalim (RP 52891) at a dose that produced no significant systemic hemodynamic effects (10 micrograms/kg plus 0.1 microgram/kg/min) resulted in a marked improvement in segment shortening in the ischemic/reperfused myocardium compared with control animals (p less than 0.05) when given before the ischemic insult. However, administration of aprikalim immediately before reperfusion had no beneficial effect. Furthermore, pretreatment with the K(ATP) channel antagonist glibenclamide antagonized the recovery of contractile function afforded by aprikalim when administered at a low dose (0.3 mg/kg) that alone had no effect on postischemic recovery. In contrast, pretreatment with either a higher dose of glibenclamide (1.0 mg/kg) or the related sulfonylurea K(ATP) channel antagonist tolbutamide (100 mg/kg) resulted in a worsening of segment function after reperfusion. The ability of aprikalim and the K(ATP) channel antagonists to alter postischemic wall function occurred independently of differences in systemic hemodynamics, area at risk, and collateral blood flow during occlusion, the major determinants of the extent of myocardial stunning. CONCLUSIONS These results suggest that opening myocardial K(ATP) channels in the ischemic heart results in a marked cardioprotective effect in stunned myocardium and that these channels may serve an endogenous function, which is to provide protection from ischemic insults.

Pharmacological evidence for a role of ATP-dependent potassium channels in myocardial stunning.