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

在短暂性脑缺血的动物模型中，海马区选择性易损性和迟发性神经元死亡(DND)已被广泛描述。众所周知，发育中的大脑对损伤有耐受性。在本研究中，我们研究了发育中沙土鼠DND损伤的临界期，以及短暂性脑缺血后一周内不同生后天数胶质细胞反应的差异均在10周龄(成年)时灌流。克氏紫染色法对DND进行组织病理学评价。3周龄前未见DND。星形胶质细胞、小胶质细胞和少突胶质细胞分别用GFAP、Mac-1和CNPase抗体进行免疫组织化学染色。在GFAP免疫染色中观察到最有趣的反应性变化。计算机图像分析显示，两例缺血型DND患者脑缺血后3d，CA1区GFAP阳性结构的面积百分比均显著增加，甚至在视网膜区外侧半侧也可见大量星形胶质细胞。锥体，刚发生DND，克氏紫染色法估计。结果提示，无论有无DND，星形胶质细胞在神经元缺血后的存活和死亡中都起着重要作用。

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.