腺苷复合潘生丁控制性降压对心肌血流及代谢的影响

Effect of dipyridamole on pharmacodynamics of adenosine.coronary hemodynamies and myocardial metabolism during adenosine-induced hypotension

在12犬对比研究腺苷(ADO)复合潘生丁(DIP)及单纯ADO降压时对心肌血流和代谢的影响。12只犬均分两组将平均动脉压(MAP)降至50%基础值持续1小时。结果DIP显著加快ADO起效速率、ADO滴速及用量减少近50%,DIP本身显著增加心叽血流,复合ADO降压时,心肌血流及氧储备的增加程度显苫高于单纯ADO降压组。认为ADO复合DIP降压有明显协同作用,可明显减少ADO用量,可改善冠脉血流动力学,有利于降压中维持心肌的氧供。

The experiment was conducted to evaluate the actions of dipyridamole (DIP) during adenosine-induced hypotension. Eighteen adult healthy mongrel dogs were randomly divided into two groups. In group Ⅰ. DIP at initial dose of 0.35 mg/kg was injected intravenously, and 10 mins later. 1% adenosine (ADO) was infused to induce the hypotension (HP). meaning that mean artcrial pressure (MAP) decreased by 50%, and HP was maintenaned with infuskin of 1%(ADO and supplemental bolus of DIP 0.15 mg/kg. In group Ⅱ. 1% ADO was only infused for induction and maintenance of HP. The blood flow of coronary sinus and cardiac output were measured by electromagnetic flowmeter, and blood samples were taken to determine blood gas analysis, hemoglobin volume and lactic acid level, immediately before ADO infusion, 30 and 60 mins during HP and at 85% recovery of MAP after ADO withdrawal, respectively. Coro nary vascular resistance index(CVRI) and the blood flow, oxygen delivcry, O_2 extraction rate and lactic acid extraction rate of myocardium (MBF, MDO2. MO_2Ext, MRLE) were calculated according to above values. As compared with those in group Ⅱ, the induction duration of HP was shorten, time between ADO withdrawal and 85% recovery of MAP was prolonged, total dosage and infusion rate of ADO decreased in group Ⅰ(P<0.05). Following HP. MBF and MDO_2 were ascended. and CVRI. MVO_2 and MO_2Ext were descended (P<0.05). MRLE kept stable(P>0.05) in both groups. In comparison correspondingly with those in group Ⅱ. MBF and MDO_2 were elevated and MO_2Ext was reduced during whole procedures (P<0.05) and MVO_2 lessened during HP(P<0.05) in group Ⅰ. It is suggested that during ADO-induced HP, DIP can potentiate the hypotensive effect of ADO. improve the coronary hemodynamies and be helpful in keeping the aerobic metabolisn of myocardium normal.