| Title | Phenylephrine produces late pharmacological preconditioning in the isolated rat heart. | | Author(s) | Naderi R, Imani A, Faghihi M | | Institution | Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, I.R.Iran. | | Source | Eur J Pharmacol 2009 Oct 29. | | Abstract | We assuming that phenylephrine produces late pharmacological preconditioning through opening of the mitochondrial K(ATP) channels. To test this hypothesis, rat hearts were isolated and perfused with Krebs buffer solution by Langendorff method and subjected to 30min regional ischemia followed by 60min of reperfusion. In this study, phenylephrine as a selective alpha(1)-adrenoceptor agonist and 5HD (5-hydroxydecanoate) as a putatively specific blocker of the mitochondrial K(ATP) channels were used. Rats were randomly divided into six groups (n=6): (I) Control: surgical procedure was performed with no ischemia/reperfusion, (II) ischemia/reperfusion: hearts underwent regional ischemia/reperfusion, (III) phenylephrine-early preconditioning: phenylephrine (50microM) was perfused for 5min prior to ischemia/reperfusion, (IV) phenylephrine-late preconditioning: rats were treated with phenylephrine (10mg/kg, i.p) 24h prior to ischemia/reperfusion, (V) 5HD-phenylephrine early preconditioning-: 5HD (100microM) was perfused for 5min prior to phenylephrine as seen in group III , (VI) Phenylephrine late preconditioning-5HD: 5HD (100microM) was perfused for 5min prior to ischemia/reperfusion as seen in group IV and (VII) 5HD- ischemia/reperfusion: 5HD (100microM) was perfused for 5min prior to ischemia/reperfusion. Compared to ischemia/reperfusion group, phenylephrine in early and late phases decreased myocardial infarct size (% of ischemia zone), reduced CK(MB) (Creatine Kinase-MB) release in the coronary effluent and improved cardiac function. Pretreatment with 5HD abolished phenylephrine-induced cardioprotection in early and late phases. It is concluded that phenylephrine-induced late cardioprotection was abolished by administration of 5HD in the isolated rat hearts. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19879872 |
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