七氟醚预处理对非糖尿病及糖尿病大鼠心肌保护效应的观察

目的观察七氟醚预处理对非糖尿病及糖尿病大鼠心肌缺血/再灌注损伤的保护效应。方法糖尿病及非糖尿病大鼠各16只,随机分为4组（n=8）：非糖尿病缺血/再灌注组（N组）,非糖尿病七氟醚预处理组（N＋S组）,糖尿病缺血/再灌注组（D组）,糖尿病七氟醚预处理组（D＋S组）。建立离体心脏缺血/再灌注损伤Langendorff灌注模型,N组及D组采用平衡灌注20 min,续灌15 min,缺血30 min,再灌注60 min,七氟醚预处理组采用平衡灌注20 min,含2.4%七氟醚的K-H液预处理10 min,洗脱5 min,缺血30 min,再灌注60 min。比较各组平衡末及再灌注15 min、30 min、60 min心率（HR）、左心室发展压（LVDP）、左心室舒张末压（LVEDP）、左心室内压最大上升和下降速率（±dp/dtmax）和再灌注末心肌梗死面积。结果平衡末N组与N＋S组间和D组与D＋S组间心功能指标（基础值）差异无统计学意义（P〉0.05）,与非糖尿病大鼠相比糖尿病大鼠心功能指标（基础值）明显下降（P〈0.05）。再灌注末N＋S组较N组心功能明显改善,心肌梗死面积减小。而D组与D＋S组以上指标差异无统计学意义。再灌注末D组较N组心功能恢复明显增强,心肌梗死面积减小。结论七氟醚预处理可以减轻非糖尿病大鼠的心肌缺血/再灌注损伤;4周病程的糖尿病大鼠基础心功能下降但对心肌缺血/再灌注损伤的耐受增强,七氟醚预处理不能进一步增强其对缺血/再灌注损伤的耐受性。

Observation on the protective effect of sevoflurane preconditioning on the myocardium in nondiabetic and diabetic rats

Objective To investigate the protective effect of sevoflurane preconditioning on isolated heart of non-diabetic and diabetic rats with ischemia/reperfusion（IR） injury.Methods 32 male SD rats（16 with diabetes and 16 without diabetes） were randomized into four groups（n=8 each）： non-diabetic rats IR group（group N）,non-diabetic rats sevoflurane preconditioning group（group N＋S）,diabetic rats IR group（group D）,diabetic rats sevoflurane preconditioning group（group D＋S）.All hearts were subjected to ischemia for 30 min followed by 60 min reperfusion.Hearts in group N＋S and D＋S were preconditioned by equilibration perfusion with K-H solution containing 2.4% sevoflurane for 10 min and followed by 5 min K-H solution washout before ischemia.The data were recorded and compared as to left ventricular end-diastolic pressure（LVEDP）,left ventricular developed pressure（LVDP）,±dp/dtmax,heart rate（HR） at end of equilibration and 15 min,30 min and 60 min of reperfusion.Myocardial infarct sizes were measured with TTC staining method at 60 min of reperfusion.Results No differences in baseline hemodynamics were observed between the former two groups and the latter two groups（P0.05）.Baseline heart functions of diabetic rats decreased as compared to those of normal hearts.Compared with group N,group N＋S demonstrated a significantly improved functional recovery（P0.05） and a significant increase in LVDP,±dp/dtmax and a large decrease in LVEDP and a significant decrease in infarct sizes.No significant statistical differences in the above parameters were observed in D and D＋S group.Meanwhile,at end of reperfusion the cardiac function recovery of D was more evident than N with a decreased infarct sizes.Conclusion Sevoflurane preconditioning can effectively attenuate ischemia/reperfusion injury to the normal isolated rat hearts.Basic heart functions were impaired in rats with 4 weeks of diabetes,while the tolerance to ischemia-reperfusion injury increased.Sevoflurane preconditioning cannot further enhance the tolerance to ischemia/reperfusion injury in diabetic rats.