单胺类递质在光化学诱导树鼩血栓性脑缺血中心区及半暗区形成中的作用

目的和方法：光化学诱导树鼠句血栓性脑缺血，用荧光分光光度法检测实验后４ 、２４ 及７２ ｈ 中心区及半暗区单胺类递质的变化，并用密度梯度法测定以上各区脑水份含量，以探讨单胺类递质代谢紊乱在缺血性脑损伤中的作用。结果：光化学反应后中心区与半暗区的多巴胺（ＤＡ） 、去甲肾上腺素（ＮＥ） 和５ － 羟色胺（５ － ＨＴ） 含量分别在４ 、２４ 及７２ ｈ 降至最低点（ 与假手术组相比Ｐ 均＜ ０－０１） ，然而５ － ＨＴ 的代谢产物—５ － 羟吲哚乙酸（５ － ＨＩＡＡ） 逐渐升高。中心区及半暗区脑水含量于实验后２４ ｈ 均达峰值（ Ｐ 均＜ ０－０１） 。结论：单胺类递质在光化学诱导树鼠句血栓性脑缺血，尤其是半暗区形成中具重要作用；其病理生理改变，既是血栓性脑缺血的结果，又是继发性脑损伤、脑水肿以及迟发性神经元坏死（ ＤＮＤ） 的原因

Effect of monoamine neurotransmitters on the formation of thrombotic ischemic core and penumbra induced by photochemistry in tree shrews

AIM and METHODS:The sequent alterations of norepinephrine (NE), dopamine(DA), 5-hydroxytryptamine (5-HT) and its metabolite 5-hydroxyindole-3-acetic acid(5-HIAA) were assessed by fluorescence spectrophotometry and water contents were measured by gravimetric technique in ischemic core, penumbra and contralateral regions at 4, 24 and 72 h after photochemical reaction in order to elucidate the mechanism of cerebral ischemic injury. RESULTS:The contents of DA, NE and 5-HT in the above regions decreased to their lowest levels at 4, 24 and 72 h , respectively ( P<0.01 ) and 5-HIAA increased gradually during ischemia ( P<0.01 ). Simultaneously, the water contents of core, penumbra reached the highest levels at 24 h ( P<0.01 ).CONCLUSION:The changes of monoamine neurotransmitter were not only the result of thrombotic cerebral ischemia, but also the reason of secondary cerebral damage, cerebral edema and delayed neuronal death.