目的 研究四氫生物蝶呤對大鼠急性心肌缺血再灌注損傷的保護(hù)作用,并探討其作用機(jī)制。方法 Wistar大鼠隨機(jī)分為對照組、假手術(shù)組、模型組及四氫生物蝶呤5、10 mg/kg組,每組10只。結(jié)扎左冠狀動脈前降支,制備急性心肌缺血再灌注損傷模型。對照組、假手術(shù)組和模型組均ig生理鹽水2 mL,四氫生物蝶呤組ig四氫生物蝶呤5、10 mg/kg。1次/d,連續(xù)給藥14 d。導(dǎo)管法測定血流動力學(xué)指標(biāo):左心室舒張最大速率(-dp/dt_max)、左心室舒張期末壓(LVEDP)、左室開始收縮至左室內(nèi)壓上升速率峰值時間(Tau);ELISA法測定血漿腦鈉素(BNP)活性;按試劑盒說明測定心肌一氧化氮合酶(eNOS)活性、NO生成量;染色法測定心肌梗死面積,計算心肌梗死程度;免疫組化法測定β3水平。結(jié)果 與模型組比較,四氫生物蝶呤5、10 mg/kg組-dp/dt_max顯著增高,LVEDP顯著降低,Tau明顯縮短,差異均具有統(tǒng)計學(xué)意義(P<0.05、0.01);血漿BNP顯著下降,eNOS活性、NO生成量均顯著升高(P<0.01);心肌梗死面積更小,心肌梗死程度更輕(P<0.01);β3表達(dá)水平升高(P<0.01)。結(jié)論 四氫生物蝶呤可以減少急性缺血再灌注損傷大鼠心肌梗死面積,改善心肌舒張功能,對大鼠急性缺血再灌注損傷具有保護(hù)作用,可能與激活eNOS活性、提高NO生成量和β3受體有關(guān)。

Objective To study protective effect of tetrahydrobiopterin against acute myocardial ischemia-reperfusion injury in rat, and discuss its mechanism. Methods Wistar rats were randomly divided into control, Sham, model, and tetrahydrobiopterin (5 and 10 mg/kg) groups, and each group had 10 rats. Rats were ligated the left anterior descending coronary artery and were established acute myocardial ischemia-reperfusion injury models. Rats in the control, Sham, and model groups were ig administrated with normal saline 2 mL, and rats in the tetrahydrobiopterin groups were ig administrated with tetrahydrobiopterin 5 and 10 mg/kg. The treatment were carried out once daily, and lasted for 14 d. Hemodynamic parameters, such as left ventricular diastolic maximum rate (-dp/dt_max), left ventricular end diastolic pressure (LVEDP), and left ventricular began to shrink to left ventricular pressure rise rate peak time (Tau) were determined by catheter method. Brain natriuretic peptide (BNP) activity in plasma was determined by ELISA method. Activity of eNOS and NO generation amounts were determined according to kit instructions. The area of myocardial infarction was determined by staining method, the degree of myocardial infarction was calculated, and the level of β3 was determined by immunohistochemistry method. Results Compared with the model group, -dp/dt_max in tetrahydrobiopterin (5 and 10 mg/kg) groups were significantly increased, LVEDP were significantly decreased, and Tau were significantly shortened, with significant difference between two groups (P < 0.05, 0.01). BNP activities in plasma were significantly decreased, activity of eNOS and NO generation amounts were significantly increased (P < 0.01). Myocardial infarction areas were smaller, the degrees of myocardial infarction were more light, and β3 expressions were significantly higher in tetrahydrobiopterin (5 and 10 mg/kg) groups (P < 0.01). Conclusion Tetrahydrobiopterin can reduce myocardial infarction area in rats with acute myocardial ischemia- reperfusion injury, improve cardiac diastolic function, and has protective effect against acute myocardial ischemia-reperfusion injury in rat, which may be related to activate eNOS activity, improve the NO generation amount and β3 receptors expression.

甘肅省自然科學(xué)基金資助項目(145RJZA174);甘肅省青年科技基金計劃資助項目(145RJYA257);甘肅省衛(wèi)生行業(yè)科研計劃項目(GSWSKY-2014-33);蘭州市科學(xué)技術(shù)局項目(2012-1-31)