糖尿病树鼩血栓性脑缺血时心脏血流动力学及心肌超微结构的变化

The Changes of heart hemodynamics and myocardium ultrastructure in cerebral ischemia tree shrews with diabetes mellitus

目的观察实验性糖尿病树鼩在血栓性局部脑缺血时心脏血流动力学及心肌超微结构的变化。方法链脲佐菌素(STZ)55mg/kg空腹腹腔注射制备糖尿病树鼩模型,一周后通过光化学反应诱导局部血栓性脑缺血。将树鼩随机分为糖尿病组,脑缺血组,糖尿病加脑缺血组,并设假手术对照组,每组8只,用多导生理仪观察左心室内压(LVSP)、左心室舒张末压(LVEDP),左心室收缩与舒张瞬间变化最大速率(±dp/dtmax),收缩动脉压(SAP),舒张动脉压(DAP)及心率(HR)。并取左心室心肌组织,行透射电镜观察心肌超微结构变化。结果 与假手术对照组相比,脑缺血组LVSP、+dp/dtmax下降(P<0.05),-dp/dtmax明显下降(P<0.01),LVEDP升高(P<0.05);糖尿病组-dp/dtmax下降(P<0.05),LVEDP明显升高(P<0.01)。与脑缺血组相比,糖尿病加脑缺血组LVSP、+dp/dtmax降(P<0.05),-dp/dtmax明显下降(P<0.01),LVEDP升高(P<0.05)。脑缺血组和糖尿病组心肌超微结构观察显示:心肌肌原纤维间水肿,一些肌原纤维可见收缩小带形成,部份线粒体固缩,部份线粒体肿胀。糖尿病加脑缺血组树鼩可见:大部分线粒体固缩,部分线粒体肿胀、嵴溶解,心肌纤维较多收缩带形成,间质充血水肿,毛细血管内皮细胞见较多空泡。结论树鼩血栓性脑缺血时伴有心脏血流动力学及心肌超微结构的异常。

Objective To observe the changes of the heart kinetics and myocardium ultrastructure in cerebral ischemia tree shrews with diabetes mellitus. Methods Inject streptozotocin(STZ) 55mg/kg to the abdominal cavity of tree shrews on an empty stomach to prepare diabetes modal, induce local thrombocerebral ischemia by photochemical reaction one week later. Divid tree shrews randomly into diabetes group (Diabetes),cerebral ischemia group (Ischemia ), diabetes with cerebral ischemia group (Diabetes and Ischemia) and the control group (Control). Every group had 8 tree shrews. The LVSP, LVEDP, ±dp/dtmax, SAP,DAP and HR were detected by multi-conducted physiometer in each experiment tree shrews. The tree shrews myocardium tissue of left ventricle was taken and observed by transmission electron microscope. Results Compare with the control, the LVSP、+dp/dtmax decrease (F<0. 05), -dp/dtmax decrease significantly(P<0. 01)and LVEDP increase (P<0. 05) in ischemia group; dp/ dtmax decrease (P<0. 05), LVEDP increase significantly (P<0. 01) in dabetes group. Compare with ischemia group, the LVSP、 +dp/dtmax decrease(P<0. 05) , -dp/dtmax decrease significantly (P<0.01)and LVEDP increase (P<0. 05) in diabetes with ceredral ischemia group. Under the transmission electron microscope, edema among myocardium myofibril, shrinkage bandelette formated in some myofibril, some mitochondrion pycnosis and swelling were observed in cerebral ischemia group and diabetes group; Pycnosis in most mitochondrion, swelling and cristae lysis in come mitochondrion, more shrinkage bandelette formated in myofibril, hyperemia and edema in interstitial and more vacuoles in the endothelial cell of blood capillary were observed in diabetes with cerebral ischemia group. Conclusion Cerebral ischemia tree shrews are always companied by abnormal heart hemodynamics and myocardium ultrastructure changes, the'encephalo- cardio -stroke'may be developed if companied by diabetes mellitus.