脑缺血时皮层扩布性抑制与心功能障碍

目的 :研究树 鼠句脑缺血时单胺氧化酶 (MAO)活化在脑缺血时心功能障碍以及扩布性抑制中的可能作用。方法 :采用光化学法诱导树 鼠句血栓性脑缺血 ,测定缺血区及血清MAO活性、多巴胺及去甲肾上腺素 (NA)水平 ,经电镜观察脑及肾上腺的超微结构。记录仪检测心率(HR)、左室收缩压峰值 (LVSP) ,左室瞬间收缩与舒张最大速率 (±dp/dtmax) ,左室舒张末期压力 (LVEDP) ,平均动脉压 (MAP)。结果 :树鼠句脑缺血过程中血清NA先升高 (由 11.60± 0 .73ng/ml升高至18.46± 0 .3 9ng/ml,P <0 .0 1) ,72h后降至 8.3 2± 1.86ng/ml;血清MAO活性逐渐升高 ,达 2 10 .1± 2 6.67U/ml(P <0 .0 1) ,72h降低至对照水平 ;心功能指标 (±dp/dtmax,LVSP ) ,尤其是HR明显降低 ,由3 17.0± 98.0 1beat/min降至 2 3 7.4± 3 1.90beat/min(P <0 .0 1) ,于2 4h恢复至对照水平。结论 :血栓性脑缺血时血清NA水平明显取决于MAO活性的变化 ,后者对脑缺血时心脏舒缩功能可能具有调节作用。

Spreading Depression and Cardiac Dysfunction After Cerebral Ischemia in Tree Shrews

Objective:To study the effect of monoamine oxidase activation o n cardiac dysfunction and possible causality of spreading depression (SD) and ce rebral-cardiac stroke after cerebral ischemia in tree shrews. Method:The focal thrombotic cerebral ischemia was induced by p h otochemical reaction in Tree Shrews.Monoamine oxidase (MAO) activities in ische mic regions and serum,and the dopamine (DA) and norepinephrine (NA) were measu red.The ultrastructure of brain and adrenal gland were observed under the el ectromicroscope.The heart rate (HR),left ventricular systolic pressure(LVSP), the maximal left ventricular contractility(±dp/dtmax),the left ventricular end -diastolic pressure (LVEDP),the mean arterial pressure( MAP) were recorded wit h a RM-6000 recorder. Results:Our results show that the level of NA in serum is s everly ascend (from 11.60±0.73 ng/ml to 18.46±0.39 ng/ml,P<0.01) and desc end to 8.32±1.86 ng/ml at 72 hours after cerebral ischemia.MAO activities i n serum is gradually ascend to 210.1±26.67 U/ml(P<0.01);it may recover to the control level at 72 hours after cerebral ischemia.The index of cardia c functions (±dp/dtmax,LVSP),especially HR is markedly decreased ( from 317.0 ±98.01 beat/min to 237.4±31.90 beat/min,P<0.01).Conclusion:The changes of the level of NA considerably depend o n MAO activities,and the latter could possess an regulative effect on the c ardiac functions after thrombotic cerebral ischemia.