甘露醇对大鼠离体心脏心功能的影响

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。

Effects of mannitol on the function in isolated hearts of rats

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.