Stretch-induced protection shares a common mechanism with ischemic preconditioning in rabbit heart.
We sought to determine whether stretch-induced preconditioning may be related to activation of adenosine receptors, ATP-sensitive K+ (K+ATP) channels, and/or protein kinase C (PKC) in the rabbit heart. Anesthetized rabbits underwent 30 min of coronary artery occlusion followed by 3 h of reperfusion. Ischemic preconditioning was induced by one episode of 5 min of ischemia followed by 5 min of reperfusion, and stretch preconditioning was induced by a transient volume overload. The abilities of gadolinium (Gd3+), a blocker of stretch-activated channels, glibenclamide (Glib), a blocker of K+ATP channels, 8-(p-sulfophenyl)-theophylline (8-SPT), a blocker of adenosine receptors, and polymyxin B (PMXB), an antagonist of PKC, to prevent the infarct size-limiting effect of stretch-induced preconditioning were evaluated. Because the infarct size-reducing effect of stretch occurred in the absence of ischemia and was prevented by previous administration of Gd3+, Glib, 8-SPT, and PMXB, we propose that activation of mechanosensitive ion channels protects the rabbit heart from subsequent sustained ischemic insult, likely through a mechanism that involves downstream activation of PKC, adenosine receptors, and/or K+ATP channels.
Gysembergh
A
A
Laboratoire de Physiologie Lyon-Nord, University Claude Bernard, France.
Margonari
H
H
Loufoua
J
J
Ovize
A
A
André-Fouët
X
X
Minaire
Y
Y
Ovize
M
M
D000818:Animals; D003326:Coronary Circulation; D004548:Elasticity; D005905:Glyburide / Q000494:pharmacology*; D006321:Heart / Q000502:physiology*; D006400:Hematocrit; D006439:Hemodynamics; D019157:Ischemic Preconditioning, Myocardial; D008465:Mechanoreceptors / Q000502:physiology; D009203:Myocardial Infarction / Q000473:pathology; D011112:Polymyxin B / Q000494:pharmacology*; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000502:physiology; D011493:Protein Kinase C / Q000502:physiology*; D058915:Purinergic P1 Receptor Antagonists; D011817:Rabbits; D018047:Receptors, Purinergic P1 / Q000502:physiology; D013806:Theophylline / Q000031:analogs & derivatives* / Q000494:pharmacology
D026902:Potassium Channel Blockers; D015221:Potassium Channels; D058915:Purinergic P1 Receptor Antagonists; D018047:Receptors, Purinergic P1; C031433:8-(4-sulfophenyl)theophylline; D013806:Theophylline; D011493:Protein Kinase C; D011112:Polymyxin B; D005905:Glyburide