Echocardiographic data: Experimental model of infarct in rats with groups: control, AHAS and AHAS + 15dPGJ.
Analysis separately for each groups There was no statistical difference in LVEF, LVES, and LVED parameters in all animals studied when compared to the baseline values. In this way, the groups were considered homogeneous. One month after scaffold implantation, the LVEF decrease significantly in control group from 33.13 ± 2.75 to 28.13 ± 3.8% (p=0.008), increased in AHAS group from 35.38 ± 2.67% to 38.88 ± 4.29% (p=0.082) and increased significantly in AHAS + 15d-PGJ2 group from 33.5 ± 5.07% to 38.88 ± 3.14% (p=0.004). The LVES, over the same time interval, increased in control group from 0.305 ± 0.178 mL to 0.380 ± 0.182 mL (p= 0.854), and decreased in AHAS group from 0.168 ± 0.039 mL to 0.161 ± 0.052 mL (p>0.9999) and in AHAS + 15d-PGJ2 group from 0.290 ± 0.143 mL to 0.179 ± 0.063 mL (p= 0.356). The LVED, over the same time interval, gave significant increases in the control group from 0.350 ± 0.362 mL to 0.569 ± 0.274 mL (p= 0.007), stabilized in AHAS group (0.260 ± 0.058 mL to 0.262 ± 0.074 mL; p>0.9999) and decrease in AHAS +15d-PGJ2 group from 0.418 ± 0.19 mL to 0.292 ± 0.094 mL (p=0.185) (Table 1).
Steps to reproduce
Myocardial infarction and Echocardiographic analysis All experiments were performed in the cell therapy laboratory of PUCPR according to the “Guidelines for the Care of Animals”, the guiding principles approved by the American Society of Physiology. Wistar rats with weights from 250 to 300 grams were intraperitoneally anesthetized using 50 mg/kg ketamine and 10 mg/kg xylazine. The animals were submitted to endotracheal intubation, without exposure of the trachea, and to mechanical ventilation at a frequency of 60 cycles/ min and a volume of 2.5 mL (“683” Harvard ® Apparatus, Inc., USA). All animals were submitted to left lateral thoracotomy and ligature of the left coronary artery with 7.0 polypropylene thread (Ethicon®, Inc., Somerville, NJ) was achieved inducing infarction of the left ventricle anterolateral wall. The detailed operation procedure was previously described by Guo-Zhong Pan et.al . The mortality rate of the animals submitted to this procedure was 20%. Seven days after myocardium infarction, the animals were again submitted to anesthesia using 50 mg/kg ketamine and 10 mg/kg xylazine intraperitoneally and a bidimensional transthoracic echocardiographic evaluation was made using a Hewlett Packard Sonos model 5500, with S12 sectorial (5-12 MHz) and 15L6 linear (7-15MHz) transducers developed for the ultrasonographic study of small animals, allowing an analysis up to 160 Hz. The transducer was placed in the left anterolateral portion of the thorax and the heart was imaged as a bidimensional axial view of the left ventricle with the mitral and aortic valves and the apex in the same image. The digital conversion of the image was obtained by a delimitation of the interventricular septum and the left ventricle posterior wall. Subsequently, the following measurements were taken: final systolic and diastolic surfaces, final diastolic and systolic lengths of the left ventricle and heart rate to calculate the final systolic volumes (LVFSV, mL), diastolic volumes (LVFDV, mL), and the left ventricle ejection fraction (LVEF %) using Simpson’s method. All the dimensions were blindly measured three times by the same echocardiologist, after which the mean of each parameter was calculated. Only animals with left ventricle ejection fractions of less than 40% were included in this study and were randomized into three groups consisting of eight animals each: control, AHAS, and AHAS+15d-PGJ2. The scaffold alone was implanted on AHAS group, and the AHAS+15d-PGJ2 nanoparticles was implanted on scaffold+15d-PGJ2 group, both on the anterolateral wall of the infarcted left ventricle (Fig. 01). Control rats underwent sham operations were carried out by the same method, but without the implantation of the amniotic membrane. All rats received perioperative analgesia after surgery and a new echocardiographic evaluation was performed after 1-month of scaffold implantation.