Pacing-induced regional differences in adenosine receptors mRNA expression in a swine model of dilated cardiomyopathy.
The adenosinergic system is essential in the mediation of intrinsic protection and myocardial resistance to insult; it may be considered a cardioprotective molecule and adenosine receptors (ARs) represent potential therapeutic targets in the setting of heart failure (HF). The aim of the study was to test whether differences exist between mRNA expression of ARs in the anterior left ventricle (LV) wall (pacing site: PS) compared to the infero septal wall (opposite region: OS) in an experimental model of dilated cardiomyopathy. Cardiac tissue was collected from LV PS and OS of adult male minipigs with pacing-induced HF (n = 10) and from a control group (C, n = 4). ARs and TNF-α mRNA expression was measured by Real Time-PCR and the results were normalized with the three most stably expressed genes (GAPDH, HPRT1, TBP). Immunohistochemistry analysis was also performed. After 3 weeks of pacing higher levels of expression for each analyzed AR were observed in PS except for A(1)R (A(1)R: C = 0.6±0.2, PS = 0.1±0.04, OS = 0.04±0.01, p<0.0001 C vs. PS and OS respectively; A(2A)R: C = 1.04±0.59, PS = 2.62±0.79, OS = 2.99±0.79; A(2B)R: C = 1.2±0.1, PS = 5.59±2.3, OS = 1.59±0.46; A(3)R: C = 0.76±0.18, PS = 8.40±3.38, OS = 4.40±0.83). Significant contractile impairment and myocardial hypoperfusion were observed at PS after three weeks of pacing as compared to OS. TNF-α mRNA expression resulted similar in PS (6.3±2.4) and in OS (5.9±2.7) although higher than in control group (3.4±1.5). ARs expression was mainly detected in cardiomyocytes. This study provided new information on ARs local changes in the setting of LV dysfunction and on the role of these receptors in relation to pacing-induced abnormalities of myocardial perfusion and contraction. These results suggest a possible therapeutic role of adenosine in patients with HF and dyssynchronous LV contraction.
Institute of Clinical Physiology, CNR, Pisa, Italy. delry@ifc.cnr.it
Silvia
S
Del Ry
Manuela
M
Cabiati
Vincenzo
V
Lionetti
Giovanni D
GD
Aquaro
Alessandro
A
Martino
Letizia
L
Mattii
Maria-Aurora
MA
Morales
D000818:Animals; D002304:Cardiac Pacing, Artificial; D002311:Cardiomyopathy, Dilated / Q000235:genetics* / Q000503:physiopathology* / Q000628:therapy; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D006333:Heart Failure / Q000235:genetics / Q000503:physiopathology; D006339:Heart Rate / Q000235:genetics; D006352:Heart Ventricles / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D012333:RNA, Messenger; D018047:Receptors, Purinergic P1 / Q000235:genetics* / Q000378:metabolism; D013552:Swine; D013556:Swine, Miniature; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology
D012333:RNA, Messenger; D018047:Receptors, Purinergic P1; D014409:Tumor Necrosis Factor-alpha