Protective Effects And Mechanisms Of Bauhinia Championii Flavones On Pituitrin-induced Acute Myocardial Ischemia In Rats

Objective:To Study the protective effects and mechanisms of pretreating BauhiniaChampionii flavones on pituitrin-induced acute myocardial ischemia in rats.Methods:1. According to different time taking heart specimens, ninety-six male SDrats were randomly divided into two tranches, then each tranche was randomlydivided into six groups of normal saline, model control, verapamil, and BCFgroups (60,120,240mg·kg-1respectively). Acute myocardial ischemia modelwas established by injecting pituitrin (0.75U·kg-1) through sublingual vein.2. The changes of ST-segment on the Ⅱ lead ECG, heart rate (HR), leftventricular end-diastolic pressure (LVEDP), the largest upstroke velocity of theleft ventricular pressure (+dp/dtmax), and the largest descendent velocity of theleft ventricular pressure (-dp/dtmax) were observed. In addition, blood andheart specimens were collected immediately after recording ECG andhemodynamic parameters, while total antioxidative capacity (T-AOC),Na+-K+-ATPase, and Ca2+-Mg2+-ATPase were detected.3.6hours after injection of pit, the contents of creatine kinase-MB(CK-MB), cardiac troponin I (cTnI), and myoglobin (MyoG) in serum wereobserved by ELISA. The expression of Cyt-C, C-fos and CaSR in myocardial tissue were detected by using reverse transcription polymerase chain reaction(RT-PCR).Results:1. Effects of different doses of BCF on ST-segment of the Ⅱ lead ECG,the hemodynamic parameters and biochemical indexesCompared with normal saline group, ST-segment on the Ⅱ lead ECG andLVEDP were elevated, T-AOC in serum, HR,+dp/dtmax,-dp/dtmaxand theactivity of Na+-K+-ATPase, Ca2+-Mg2+-ATPase were decreased in model controlgroup. However, Compared with model control group, BCF could significantlysuppress the elevation of ST-segment at15s,1min. and LVEDP after injectingpit, while increased the level of T-AOC in serum, HR,+dp/dtmax,-dp/dtmaxandthe activity of Na+-K+-ATPase, Ca2+-Mg2+-ATPase. Meanwhile, it could reducethe contents of CK-MB, cTnI and MyoG in a dose dependent manner (P <0.05or P <0.01).2. Effects of Bauhinia championii（Benth）Benth flavones (BCF) on theexpression of Cyt-C, c-fos and CaSR in acute myocardial ischemia ratsCompared with normal saline group, the expression of Cyt-C, C-fos andCaSR were increased in model control group. Compared with model controlgroup, BCF could significantly reduce the expression of Cyt-C, C-fos and CaSR.Conclusion: BCF has obvious protective effects on pituitrin-induced acutemyocardial injury in rats, which might be related with improving myocardialcontractile and relaxation function, antioxidation, restrainning calciumoverloading, reducing myocardial injury, and inhibitting cell apoptosis.