[Effects of tian-ma injection on myocardial ischemia and lipid peroxidation in rabbits].

Lipid peroxidation initiated by oxygen free radicals played an important role in the pathogenesis of coronary heart disease. The purpose of this study was to explore the effects of Tian-Ma (Gastrodia elata Bl.) injection on myocardial infarct size and lipid peroxidation by observing serum malondialdehyde (MDA) levels. Twenty-six New Zealand rabbits were divided into control group (n = 6), ischemic group (n = 10), and Tian-Ma treated group (n = 10). Left ventricular branch (LVB) of coronary artery was ligated at its middle third in ischemic and treated groups. LVB was not ligated in control group. Tian-Ma injection was given intravenously (1 mg/kg) every 8 hours after ligation in treated group for 48 hours. Precordial 12-lead ECG mapping was recorded before operation and at 3, 24 and 48 hours after occlusion. Hemodynamic changes (HR, LVP) were monitored before and 0.5, 3 and 48 hours after ligation. Serum MDA levels were determined by thiobarbituric acid spectrophotometry before operation, and 0.5, 3, 9, 24, and 48 hours after ligation. Dual staining technique was used 48 hours after ligation to determine the area at risk and infarct size. The results showed that Tian-Ma injection did not decrease sigma ST elevation (P greater than 0.05), but NQ was significantly lower during ischemia in treated group (P less than 0.01), Tian-Ma injection reduced the area at risk by 23.5% (P less than 0.05) and infarct size by 34.5% (P less than 0.01). Tian-Ma injection significantly decreased the levels of serum MDA 24 and 48 hours after occlusion (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)