甘露醇对大鼠离体心脏心功能的影响

Effects of mannitol on the function in isolated hearts of rats

目的:研究甘露醇对离体大鼠心脏心功能的影响。方法:应用Langendorff大鼠离体心脏灌流方法。32只雄性SD大鼠,随机分为4组:对照组,甘露醇20mmol/L组,甘露醇40mmol/L组,甘露醇60mmol/L组,每组8只。连续记录用药后60min冠状动脉流量、心脏收缩期左室主动收缩压(left ventricular developed pressure,LVDP)、左心室内压上升的最大变化速率(+dp/dtmax)、心率与左室主动收缩压的乘积(RPP)、舒张期左心室内压下降的最大变化速率(-dp/dtmax)及左心室舒张末压(left ventricular end-di-astolic pressure,LVEDP)并进行统计分析。结果:与用药前相比,甘露醇20mmol/L组随着作用时间延长,可逐渐升高LVDP、+dp/dtmax、RPP,60min时达最高。甘露醇40mmol/L升高LVDP,+dp/dtmax、RPP,30min左右达高峰后逐渐降低。甘露醇60mmol/L升高LVDP,+dp/dtmax、RPP,10min左右达高峰,随后衰减。高浓度甘露醇升高LVEDP,降低-dp/dtmax。结论:不同浓度甘露醇对左心室收缩功能的影响具有时间依赖性。高浓度甘露醇减弱左心室舒张功能。

AIM： To observe the effects of mannitol in isolated rat hearts.METHODS： The langendorff system was used to evaluate the function of rat hearts treated with mannitol（20 mmol/L,40 mmol/L and 60 mmol/L respectively）.Following a stabilization period of 30 min, the isolated hearts were subjected to continuous perfusion for a further 60 min with vehicle or increasing concentration of mannitol.Heart functional indexes including left ventricular develop pressure（LVDP）,rate-pressure product（RPP）,maximal rate of pressure increased（＋dpp/dtmax）,maximal rate of pressure decreased（-dp/dtmax）,left ventricular end diastolic pressure（LVEDP） and coronary flow were recorded. RESULTS：LVDP,＋dp/dtmax and RPP were increased significantly in hearts perfused with 20 mmol/L mannitol in a time dependent manner.However,when the hearts perfused with 40 mmol/L or 60 mmol/L mannitol,time used for reaching the maximum LVDP,＋dp/dtmax and RPP by 40 mmol/L and 60 mmol/L mannitol was shorter in hearts treated with 20 mmol/L mannitol.More,the results demonstrated that heart treated with 60 mmol/L mannitol could significantly increase the LVDEP and decrease the-dp/dtmax. CONCLUSION： Mannitol could affect left ventricular contraction function in a time and concentration dependent manner.Ventricular diastolic function was weakened by perfusing the high concentration of mannitol.