[Role of mitochondrial permeability transition pore in mediating the effect of endomorphin-1 postconditioning against myocardial ischemia-reperfusion injury in rats].

Abstract

OBJECTIVE:

To investigate the role of mitochondrial permeability transition pore (MPTP) opening in mediating the effect of endomorphine-1 postconditioning to alleviate myocardial ischemia-reperfusion (IR) injury in rats.

METHODS:

Forty-five male SD rats were randomized equally for sham operation, myocardial IR injury, endomorphin-1 postconditioning, atractyloside (a MPTP opener) postconditioning, or endomorphin-1 + atractyloside postconditioning. The hemodynamic param-eters of the rats were monitored in real time via carotid artery cannulation to the left ventricle. After reperfusion, plasma samples were collected for biochemical analyses. The size of myocardial infarct area was detected using Evans blue and TTC double staining, and the myocardial expressions of apoptosis-related proteins Bax, Bcl-2 and cleaved caspase-3 were analyzed using Western blotting.

RESULTS:

Myocardial IR injury resulted in significantly decreased heart rate and blood pressure in the rats (P<0.05). Compared with those in IR group, the rats with endomorphin-1 postconditioning showed significantly increased heart rate and blood pressure (P<0.05), lowered contents or activities of LDH, CK-MB, cTnI, IL-6, TNF-α, Cyt-C and MDA in the plasma (P<0.05), increased plasma SOD activity (P<0.05), reduced size of myocardial infarction, decreased myocardial expression of Bax and cleaved caspase-3 protein (P<0.05), and increased myocardial expression of Bcl-2 protein (P<0.05). All these changes induced by endomorphin-1 were obviously reversed by atractyloside postconditioning (P<0.05).

CONCLUSION:

Endomorphin-1 postconditioning protects against myocardial IR injury in rats probably by inhibiting the opening of MPTP and reducing cardiac myocyte apoptosis via down-regulating cleaved caspase-3 expression.

• Authors: Yan-Ping Huang, Tian-Hua Yang, Zhi-Yan Jin, Ya Wang, Hong-Wei Ye, Qin Gao, Zheng-Hong Li
• Journal: Nan fang yi ke da xue xue bao = Journal of Southern Medical University (Nan Fang Yi Ke Da Xue Xue Bao) Vol. 38 Issue 5 Pg. 547-553 (May 20 2018) ISSN: 1673-4254 [Print] China
• PMID: 29891450 (Publication Type: Journal Article)

Chemical References

• Enzyme Inhibitors
• Mitochondrial Membrane Transport Proteins
• Mitochondrial Permeability Transition Pore
• Oligopeptides
• endomorphin 1
• Atractyloside

Topics

• Animals
• Atractyloside (pharmacology)
• Blood Pressure (drug effects)
• Enzyme Inhibitors (pharmacology)
• Heart Rate (drug effects)
• Ischemic Postconditioning
• Male
• Mitochondrial Membrane Transport Proteins (drug effects, physiology)
• Mitochondrial Permeability Transition Pore
• Myocardial Reperfusion Injury (blood, pathology, prevention & control)
• Oligopeptides (pharmacology)
• Random Allocation
• Rats
• Rats, Sprague-Dawley