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BACKGROUND AND AIMS: The present study conducted from March 2012 to July 2013 aimed to evaluate from echocardiographic point of view the effects of peripheral intravenous administration of mesenchymal stem cells (MSCs) in laboratory rabbits presenting 30 days old chronic myocardial infarction. MATERIAL AND METHODS: 30 days after the induction of an acute myocardial infarction in 40 laboratory rabbits by direct ligation of the left anterior descending coronary artery at about 10 mm from the apex, we injected 1×106 MSCs in the auricular vein in a group of 30 rabbits, and a group of 10 rabbits were used as controls. 30 days after the injection of stem cells the left ventricular (LV) fractional shortening (FS) was evaluated by echocardiography and compared with the control rabbits. RESULTS: In control rabbits, echocardiography revealed akinesis of apex, interventricular septum kinetics was also impaired, FS being approximately 6%. In 80% (24 rabbits) of the injected rabbits the FS of the LV was significantly greater than in the witness group (26+/-2%, p<0.0001). At 13.3% (4 rabbits) of the injected rabbits the FS of the LV showed no improvement in comparison with the control group (6.5+/-1%). CONCLUSION: An improvement of LV SF 30 days after MSCs were injected(p<0.0001) was noted. We have to further determine if this improvement of the LV function is correlated with any histopathological changes and if it is not lost in time. Also, further studies needs to evaluate if there is any significant change in the overall mortality.
RESUMEN
INTRODUCTION: Ischemic heart disease is a major public health problem in western countries. Appropriate animal experimental models of chronic myocardial infarction is an essential first step in order to investigate and develop new therapeutic interventions. AIM: The aim of this study was to find an optimal place for a coronary artery ligation to induce an optimal chronic myocardial infarction and also a new heart approach that will not require oro-tracheal intubation. MATERIAL AND METHODS: To achieve these goals we used a group of rabbits and after induction of anesthesia and cardiac exposure by rib osteotomy (rib III, IV and V) at the costo-sternal junction level on the right side we performed three different left anterior descending artery (LAD) ligation at different distances (5, 10 and 15 mm) in relation to the apex. Thirty days after the acute myocardial infarction, we correlated laboratory investigations (serology, ECG, cardiac ultrasound) with histopathological findings. RESULTS: Heart approach achieved by rib osteotomy (rib III, IV and V) at the costo-sternal junction level on the right side, maintains the integrity of the ribcage, allowing it to take part in respiratory movements and the animal model does not need oro-tracheal intubation. Ligation of LAD at 15 mm from the apex was incompatible with life; ligation of LAD at 5 mm from the apex does not achieved transmural myocardial infarction and ligation of LAD at 10 mm from the apex achieved a transmural myocardial infarction of the left ventricle which also involved the distal part of the interventricular septum. CONCLUSION: Ligation of LAD at 10 mm from the apex achieved a transmural myocardial infarction of the left ventricle, is in an easily accessible area from technical point of view, it is sufficiently expanded to induce hemodynamic effects that can be quantified with paraclinical examination and also it is compatible with the experimental animal life. If the heart is approached by rib III, IV and V osteotomy at the costo-sternal junction level on the right side combined with neuroleptic anaesthesia, the animal does not need assisted ventilation.
