The experimental research of the safety of the circulatory arrest under the deep hypothermia

在短暂性缺血动物模型中，海马的选择性易感性和延迟性神经元死亡（DND）已被广泛描述。众所周知，发育中的大脑对损伤具有耐受性。在本研究中，我们研究了发育中的沙鼠DND损伤的关键阶段，以及在出生后10周龄（成虫）灌注不同时期短暂缺血后一周内胶质细胞反应的差异。采用甲蓝紫染色对DND进行组织病理学评价。3周前未见DND。用GFAP抗体、Mac-1抗体和CNPase抗体分别检测星形胶质细胞、小胶质细胞和少突胶质细胞的免疫组织化学反应。GFAP免疫染色观察到最有趣的反应性变化。计算机图像分析显示，缺血3天后，两例DND缺血性病例CAI区gmap阳性结构面积分数均显著增加，经紫染色估计，即使在DND刚刚发生的锥体侧半部分也可见大量星形细胞。提示星形胶质细胞在有或无DND的缺血后神经元存活和死亡中起重要作用。

In animal models of transient ischemia, selective vulnerability and delayed neuronal death (DND) in the hippocampus have been extensively described. It is well known that the developing brains have tolerance to damage. In the present study, we investigated the critical stage of the damage of DND in the developing gerbils and the differences of glial reactions within a week after transient ischemia in various postnatal days were all perfused at 10 weeks-old (adult). Histopathological evaluation of DND was performed by cresil violet staining. DND was not seen before 3 weeks-old. Glial reactions were examined immunohistochemically by the antibodies against GFAP, Mac-1 and CNPase, for astrocyte, microglia and oligodendrocyte, respectively. The most interesting reactive changes were observed in GFAP immunostaining. Computer image analysis showed that area fraction of GFAP-positive structures in CAI region was significantly increased in both ischemic cases with DND in 3 days after ischemia, the numerous astrocytes were observed even in the lateral half of st. pyramidalis, in which DND was just occurring, as estimated in cresil violet staining. The findings suggest that the astrocytes play an important role in neuronal survival and death after ischemia in both cases with and without DND.