Increased myocardial vulnerability to ischemia-reperfusion injury in the presence of left ventricular hypertrophy

Autor: Barbara Faricelli, Søren Mølgaard, Max Salomonsson, Thomas Engstrøm, Marek Treiman
Rok vydání: 2016
Předmět:
0301 basic medicine
Male
medicine.medical_specialty
Physiology
Ischemia
Myocardial Infarction
Myocardial Reperfusion Injury
030204 cardiovascular system & hematology
Left ventricular hypertrophy
Incretins
Rats
Inbred WKY

Severity of Illness Index
Electron Transport Complex IV
03 medical and health sciences
Electron Transport Complex III
0302 clinical medicine
Internal medicine
Rats
Inbred SHR

Severity of illness
Internal Medicine
medicine
Animals
cardiovascular diseases
Myocardial infarction
Left ventricle hypertrophy
High prevalence
business.industry
Venoms
Myocardium
Heart
medicine.disease
Infarct size
Rats
030104 developmental biology
Hypertension
cardiovascular system
Cardiology
Cytochromes
Exenatide
Hypertrophy
Left Ventricular

Cardiology and Cardiovascular Medicine
business
Peptides
Reperfusion injury
Zdroj: Journal of hypertension. 34(3)
ISSN: 1473-5598
Popis: Despite its high prevalence among patients suffering myocardial infarction, the significance of left ventricle hypertrophy for infarct size is not known. We asked whether infarct size might be increased by this condition, and whether any such increase might be associated with an increased mitochondrial damage following coronary occlusion.Occlusion of the left descending artery in isolated, perfused hearts of SHR-SP (spontaneously hypertensive rat stroke-prone) (left ventricular hypertrophy) or Wistar-Kyoto (WKY) (control) rats was used, followed by reperfusion with or without exendin-4 (Exe-4), a glucagon-like peptide-1 receptor agonist. Infarct size relative to area-at-risk was determined. Separately, mitochondria were isolated after global ischemia. Activities of complexes III and IV and amounts of selected complex subunits and cytochromes a, b, c, and c1 were determined.Infarct size (ischemia 35 min and 120 min reperfusion) was 65.8% (±3.3%) and 37.1% (±3.4%) in the SHR-SP and WKY hearts, respectively (P 0.05). Exe-4 significantly decreased infarct size and hypercontracture in WKY, but not in SHR-SP, hearts. After ischemia 15 min in SHR-SP hearts, Exe-4 reduced the infarct (26.6%, ±3.8% to 9.3% ± 1.5%; P 0.05). Mitochondria from postischemic SHR-SP hearts showed a reduction of complex III (368.1 ± 37.5 to 175.8 ± 23.0 nmoles/min × mg; P 0.05) and complex IV (14.4 ± 0.22 to 5.8 ± 0.8 1/s × mg; P 0.05) activities and decreased amounts of cytochromes a, b, and c.Hearts from hypertensive (SHR-SP) rats with left ventricle hypertrophy appeared more vulnerable to ischemia-reperfusion injury, as supported by a more profound infarct development and an earlier loss of postconditioning by Exe-4. Mitochondrial complexes III and IV were identified among possible loci of this increased, hypertrophy-associated vulnerability.
Databáze: OpenAIRE