[Effect of salvianolic acid A on anesthetized canine experimental myocardial infarction]

Salvianolic acid A (SAA), one of the major active water-soluble salvianolic acids of traditional Chinese medicine Salvia miltiorrhiza Bunge, has been reported to be effective on anti-myocardial ischemia, anti-oxidation and anti-thrombus. This study aimed to investigate appropriate administration route on dogs with acute myocardial ischemia(AMI). Twenty-four dogs were randomized into four groups (n=6), model, oral administration of SAA (8 mg•kg⁻¹), intravenous administration of SAA (4 mg•kg⁻¹), intravenous administration of Herbesser(0.5 mg•kg⁻¹) as positive drug group. AMI model was established by ligating left anterior descending coronary arteries(LAD) of dogs. Changes of ST segment were determined by epicardial electrocardiogram(ECG), coronary blood flow (CBF) and myocardial oxygen consumption were measured by ultrasonic Doppler flow meter, serum creatine kinase (CK) and lactate dehydrogenase (LDH) were observed by fully automatic biochemical analyser. Myocardial infarct size was assessed by nitro blue tetrazolium (NBT) staining. Both oral and intravenous administration of SAA reduced the myocardial infarct area/left ventricle area significantly [(16.73±6.52)% and (13.19±2.38)%, compared with (24.35±4.89)% in model group, P<0.01). Oral administration of SAA improved the ECG performance of Σ-ST from 30-190 min after ischemia (P<0.05-0.01), while intravenous SAA had a rapid onset (10-190 min after ischemia, P<0.05-0.01). Compared with model group, oral and intravenous SAA both decreased serum CK and LDH significantly (P<0.05-0.01), while the difference of intravenous administration is more significant. SAA protects myocardium in canine experimental myocardial infarction models. Intravenous administration of SAA alleviates myocardial infarction with greater significance than oral route.