Canine Model for Myocardial Infarction (MI)

Intravenous anesthesia with 3% pentobarbital sodium at a dose of 30mg/kg, then insert the tracheal tube. Fix the dogs to right lying position, isolate femoral artery and femoral vein to seperately used to measure peripheral arterial pressure and to the test sample and supplemental anesthesia [3% pentobarbital sodium 10ml by adding 500 ml of saline) at a rate of (5 ml/kg·h). Isolated right jugular vein for intubation of heparin. From the 4th, 5th intercostal thoracotomy, cut the pericardium, expose the heart, separate the left branch (LCX). From the root to the first main branch, ligature all the rest of the small branches, separation length is nearly 2cm, hook the appropriate electromagnetic flowmeter probe (2mm), continuously record the left-handed blood flow. Draw a filament line under LCX, lift the thread to block the blood flow for 20s, observe and record the traffic changes. Lay down the thread so that the blood is fully filled and the flow is the peak flow. Place 2-3 small silver clip on the LCX, adjust the silver folder, so that blood flow reduced to about 30% of peak flow(reduce to 8ml/min in this test). Start the electrical stimulation when the flow is stable. The electric stimulation needle should be made of stainless steel, the tip of the electrode penetrates the LCX vessel wall and extends into the lumen and fixed to determine that its tip is in intimate contact with the arterial intima. Electronically stimulated DC current of 150 μA, continued until LCX blood flow reduced to 0 and continued for 3mins. Electrical stimulation time is at least 15mins, and record the time for the blood flow to block the time. In the screening of samples, after treatment to see the recovery time for the start of administration to LCX flow recovery to the electrical stimulation before the flow of 1/3 of the time. The resistance time is from re-pass to LCX traffic reduce to zero again. At the end of the trial, the animals were sacrificed and cut the LCX segment long enough to open, remove the thrombus for weighing.

SPSS software is used for statistical analysis, measurement data to mean ± standard deviation (x ±ｓ), using t test and single factor analysis of variance for group comparison , P<0.05 indicates there was a significant difference, P<0.01 indicates there are very significant differences.