Abstract |
Glibenclamide-induced closure of ATP-dependent potassium ( KATP) channels decreases coronary blood flow during normoxic and post-ischemic conditions. We have found that post-ischemic cardiac function is improved after glibenclamide treatment. Our theory was that this is a result of higher intracellular calcium concentrations due to reduction in ischemia-mediated hyperpolarization of the myocardial cell membrane. We hypothesized therefore that opening KATP channels would reduce post-ischemic function in our isolated, erythrocyte perfused, working rat heart model. During treatment with 1 or 12 mumol.L-1 pinacidil ( protein unbound concentration) both before and after 12 minutes global ischemia coronary blood flow increased 2-3 fold compared with vehicle, while cardiac functional recovery post-ischemically was improved with both concentrations. Because closing and opening cardiac KATP channels both improve post-ischemic function, our calcium theory above can be discounted. The protective effect of glibenclamide may possibly be ascribed to metabolic effects such as preservation of ATP levels during ischemia.
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Authors | Roger J Legtenberg, Ralph J Houston, Paul Smits, Berend Oeseburg |
Journal | Advances in experimental medicine and biology
(Adv Exp Med Biol)
Vol. 530
Pg. 519-26
( 2003)
ISSN: 0065-2598 [Print] United States |
PMID | 14562747
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Potassium Channels
- Pinacidil
- Glyburide
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Topics |
- Animals
- Glyburide
(pharmacology)
- Heart
(drug effects)
- In Vitro Techniques
- Ion Channel Gating
(drug effects)
- Male
- Myocardial Ischemia
(prevention & control)
- Pinacidil
(pharmacology)
- Potassium Channels
(drug effects, physiology)
- Rats
- Rats, Wistar
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