乐果对大鼠心血管功能影响的实验研究

目的观察不同剂量的乐果在不同时点对大鼠心血管功能的影响。方法复制SD大鼠乐果急性中毒动物模型，用动脉和左心室插管的方法，观察正常及腹腔注射染毒后30，60，90，120min时动物心率(HR)、最高左心室内压(Peak)、左心室内压最大上升速率( dp／dt max)、心力环面积(L0)、舒张压和收缩压等指标的变化。结果高剂量染毒组(90mg／kg)大鼠心率在30min时开始下降，直到观察结束降为染毒前的88％，收缩压和舒张压在染毒后120min分别降到染毒前的81％和71％。而中剂量染毒组(60mg／kg)大鼠的 dp／dt max、Peak值和L0在观察结束时均显著高于染毒前。低剂量染毒组(30mg／kg)大鼠各个指标未见显著性改变。结论中剂量的乐果可以增强心肌收缩力，而高剂量的乐果抑制大鼠心血管功能。

Effects of Dimethoate on Cardiovascular Function of Rats

Objective To study the effects of dimethoate on cardiovascular function of rats.Methods Artery and ventricle cannulation was employed to measure physiological parameters including blood pressure,heart rate,peak, +dp/dt max , and L0,etc.The anesthetic male Spraque Dawley rats were treated with dimethoate at dose of 0(saline),30,60 and 90 mg/kg,then parameters were recorded at 0,30,60,90,and 120 min after administration.Results The heart rate of rats in high dose group began to decline at 30 minutes and decreased to 88 percent of that at pre administration till to the end of observation.The systolic and diastolic pressures descended 19% and 29% in contrast to that at the pre administration,respectively.The values of +dp/dt max ,peak and L0 of rats in medium group were significantly higher at 120 minutes after administration of that at the pre administration.Conclusions Dimethoate in medium dose shows positive effect on the cardiovascular systems,however,in high dose inhibits the function of cardiovascular systems.