Abstract
K(ATP) channels are activated predominantly in the epicardium during regional ischemia. Therefore, the role of K(ATP) channels in ischemia-induced rise of extracellular potassium concentration ([K+]o) might be greater in the epicardium. In 18 anesthetized dogs, the left anterior descending coronary artery (LAD) was ligated, followed by injection of 23-microm latex beads into the occluded artery to interrupt collateral flow, by which accumulated [K+]o might wash out. Epicardial and endocardial [K+]o were measured during a 20-minute period of ischemia using a valinomycin membrane. The dogs were divided into three groups: 6 control dogs (CTRL); 7 dogs pretreated with intravenous glibenclamide (0.3 mg/kg [GLIB]), a blocker of K(ATP) channels; and 5 dogs pretreated with intravenous nicorandil (0.2 to 0.25 mg/kg [NCR]), a K(ATP) channel opener. Before LAD occlusion, there was no difference in [K+]o among the three groups. In the control group, epicardial and endocardial [K+]o were increased to a similar level as a function of time after occlusion (CTRL) at both layers. Ischemia-induced epicardial [K+]o rise was suppressed by GLIB (8.4+/-0.4 vs 6.7+/-0.5 mM, P < 0.05) but augmented by NCR (12.9+/-2.0 mM, P < 0.05). In contrast, endoca...Continue Reading
References
Aug 1, 1991·Circulation·D T ManganoB Massie
Jun 1, 1991·Circulation Research·T FurukawaR J Myerburg
Feb 1, 1990·Circulation Research·P F KantorL H Opie
May 1, 1990·American Heart Journal·S S BekheitN el-Sherif
Oct 1, 1990·Circulation Research·A A WildeM J Janse
Dec 1, 1988·Cardiovascular Research·P TaggartR W Emanuel
Mar 1, 1989·Circulation Research·T Miyazaki, D P Zipes
Jun 1, 1987·Cardiovascular Research·H MoriY Nakamura
Aug 1, 1986·Circulation·S KimuraR J Myerburg
Nov 1, 1973·Circulation Research·P L FriedmanA L Wit
Dec 1, 1973·Circulation Research·R LazzaraB J Scherlag
Apr 1, 1983·Circulation Research·A G Kléber
Jul 1, 1981·Circulation Research·D E EulerE N Moore
Jul 1, 1981·Circulation·B Gondi, N C Nanda
Nov 1, 1981·Journal of Pharmacological Methods·D C WarltierH L Brooks
Jun 1, 1980·Circulation Research·R F Gilmour, D P Zipes
Jul 15, 1995·Circulation·R F RedbergJ Kane
Oct 1, 1994·Cardiovascular Drugs and Therapy·K MoritaniS Ogawa
Dec 1, 1993·Circulation·A Lukas, C Antzelevitch
May 1, 1993·Circulation Research·V M FigueredoS A Camacho
Citations
Apr 3, 2012·American Journal of Physiology. Heart and Circulatory Physiology·Tyson G TaylorAlexey V Zaitsev
Sep 21, 2005·Heart Rhythm : the Official Journal of the Heart Rhythm Society·Ziad F IssaDouglas P Zipes
Oct 8, 2011·Circulation Research·Talha A FaridKumaraswamy Nanthakumar
Oct 13, 2009·American Journal of Physiology. Heart and Circulatory Physiology·Stéphane MasséKumaraswamy Nanthakumar
Jul 23, 2013·American Journal of Physiology. Heart and Circulatory Physiology·Tyson G TaylorAlexey V Zaitsev
Oct 9, 2007·American Journal of Physiology. Heart and Circulatory Physiology·Junichi ShimokawaHiroyuki Tsutsui