H_2O_2对大鼠心功能的影响与药物的保护作用

EFFECTS OF H2o2 ON HEART AND PROTECTION OF CICAPROST AGAINST H2O2-INDUCED MYOCARDIAL INJURY IN ISOLATED RAT HEARTS

利用大鼠离体心脏Ｌａｎｇｅｎｄｏｒｆｆ模型观察了Ｈ＿２Ｏ＿２对心功能的影响和药物的保护作用，结果表明低浓度Ｈ＿２Ｏ＿２（０．１０，０．２５ｍｍｏＬ／Ｌ）能增加冠脉流量（ＣＦ），左室内压和左室＋ｄｐ／ｄｔｍａｘ；高浓度Ｈ＿２Ｏ＿２（１．００ｍｍｏ１／Ｌ）则出现与上述相反的作用；低或高浓度Ｈ＿２Ｏ＿２灌流５ｍｉｎ后再用正常ＫＨ液灌流３０ｍｉｎ，均使ＣＦ减少，心功能降低，心肌组织中丙二醛增加，磷酸肌酸激酶活性降低，ＡＴＰ含量减少。Ｃｉｃａｐｒｏｓｔ、甘露醇、过氧化氢酶能明显减轻Ｈ＿２Ｏ＿２所致的心肌损伤。

Effects of H2O2 on cardiac function and the protectioii of Cicaprost,a stable mimetic ofprostacyclin,against H2O2-induced myocardial inujries were studied in isolated rat hearts. The hearts were perfused with various concentrations of H2O2-containing Kreb's-Hcnseleit(KH)solution,It was found that lower concentration of H2O2(0.10,0.25mmol/L)increasedcoronary flow,left ventricle pressure(LVF), and left ventricie+dp/dtmax,In contrast,high-er concentratiOn of H2O2(1.00 mmol/L)depressed cardiac performances;after 5 min ,perfus-sion of hearts with lower or higher concentration of H2O2 solution followed by 30 min perfu- sion with normal KH solution resulted in significant depression of cardiac performances,asso- ciated with ventricular arrhythias,decrease of myocardial ATP content and creatine kinaseactivities,as well as the rise of myocardial malondialdehyde(MDA)content.Cicaprost(277nmolL),Mannital(25mmol/L),Catalase(2 mg/L)could alleviate H2O2-induced car-diac damages,inhibit increase of myocardial MDA and decrease ATP content and CK ac-tivites. It was postulated that H2O2-induced myocardial injuries may be mediated by bothH2O2 itself and hydroxyl radical(·oH).The Protective effects of Cicaprost against H2O2-in-duced myocardial injuries may be mainly through scavenging·OH and anti-lipid peroxida-tion,and also through increasing coronary flows.