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Research
Role of dopamine D2 receptors in ischemia/reperfusion induced apoptosis of cultured neonatal rat cardiomyocytes
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* Corresponding authors: Bao-feng Yang xucq45@126.com - Chang-qing Xu xucq45@126.com
- † Equal contributors
1 Department of Pathophysiology, Harbin Medical University, Harbin, PR China
2 Department of Child Cerebral Palsy, The Third Clinical Hospital of Jiamusi University, Jiamusi, PR China
3 The first Hospital, Harbin, PR China
4 Department of Physiology, Wenzhou Medical College, Wenzhou, PR China
5 Department of Pathophysiology, Qiqihar Medical University, Qiqihar, PR China
6 Department of Biology, Lakehead University, Thunder Bay, Ont., Canada P7B5E1
7 Department of Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada S7H 5E5
8 Department of Pharmacology, Harbin Medical University, Harbin, PR China
9 Bio-pharmaceutical Key Laboratory of Heilongjiang Province, Harbin, PR China
Journal of Biomedical Science 2011, 18:18 doi:10.1186/1423-0127-18-18
Published: 16 February 2011Abstract
Background
Myocardial ischemia/reperfusion injury is the major cause of morbidity and mortality for cardiovascular diseases. Dopamine D2 receptors are expressed in cardiac tissues. However, the roles of dopamine D2 receptors in myocardial ischemia/reperfusion injury and cardiomyocyte apoptosis are unclear. Here we investigated the effects of both dopamine D2 receptors agonist (bromocriptine) and antagonist (haloperidol) on apoptosis of cultured neonatal rat ventricular myocytes induced by ischemia/reperfusion injury.
Methods
Myocardial ischemia/reperfusion injury was simulated by incubating primarily cultured neonatal rat cardiomyocytes in ischemic (hypoxic) buffer solution for 2 h. Thereafter, these cells were incubated for 24 h in normal culture medium.
Results
Treatment of the cardiomyocytes with 10 μM bromocriptine significantly decreased lactate dehydrogenase activity, increased superoxide dismutase activity, and decreased malondialdehyde content in the culture medium. Bromocriptine significantly inhibited the release of cytochrome c, accumulation of [Ca2+]i, and apoptosis induced by ischemia/reperfusion injury. Bromocriptine also down-regulated the expression of caspase-3 and -9, Fas and Fas ligand, and up-regulated Bcl-2 expression. In contrast, haloperidol (10 μM) had no significant effects on the apoptosis of cultured cardiomyocytes under the aforementioned conditions.
Conclusions
These data suggest that activation of dopamine D2 receptors can inhibit apoptosis of cardiomyocytes encountered during ischemia/reperfusion damage through various pathways.