Involvement of potassium channel in hemin-induced cardioprotection in rat hearts / 浙江大学学报·医学版
Journal of Zhejiang University. Medical sciences
;
(6): 7-12, 2007.
Article
in Chinese
| WPRIM
| ID: wpr-271583
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of heme oxygenase 1 inducer hemin on protection of ischemia-reperfusion injury in rats and its mechanisms.</p><p><b>METHODS</b>The Langendorff model of isolated rat heart was used; the left anterior descending coronary artery was occluded for 30 min and subsequently reperfused for 2 h. Then the ventricular function and infarct size were measured.</p><p><b>RESULT</b>Hemin preconditioning prevented the increase in LVEDP, decrease in LVDP and +/- dp/dt(max) in the isolated ischemia-reperfusion rat hearts. The leakage of LDH and CK in the coronary effluent was significantly declined in hemin-treated rat hearts. And the infarct size was also reduced. Administration of a blocker of mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) 5-HD (5 mg/kg) before hemin preconditioning increased the LVEDP, and reduced the LVDP and +/- dp/dt(max). The leakage of LDH and CK in the coronary effluent and the infarct size were also increased compared with only hemin-treated rat hearts. Pretreatment of the rats with a blocker of sarcolemmal ATP-sensitive potassium channel (sarcK(ATP)) HMR-1098 (6 mg/kg) before hemin preconditioning also abolished the protective effect. Infusion of paxilline (1 micromol/L), a blocker of calcium activated potassium channel (K(Ca)) for 10 min before ischemia/reperfusion led to larger infarct size and poorer myocardial performance as compared with the hemin group. The leakage of LDH and CK in the coronary effluent was also increased.</p><p><b>CONCLUSION</b>Both mitoK(ATP)and sarcK(ATP)channels activation are required for the delayed cardioprotection induced by hemin. The opening of K(Ca) channels-dependent mechanism may be involved in the protection.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Pharmacology
/
In Vitro Techniques
/
Cardiotonic Agents
/
Myocardial Reperfusion Injury
/
Potassium Channels
/
Rats, Sprague-Dawley
/
Ischemic Preconditioning, Myocardial
/
Potassium Channels, Calcium-Activated
/
Potassium Channel Blockers
/
Heme Oxygenase-1
Limits:
Animals
Language:
Chinese
Journal:
Journal of Zhejiang University. Medical sciences
Year:
2007
Type:
Article
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