Nakashima K, Yamashita K, Uesugi S, Ito H
Department of Neurosurgery, Yamaguchi University School of Medicine, Japan.
J Neurotrauma. 1999 Feb;16(2):143-51. doi: 10.1089/neu.1999.16.143.
Apoptosis is involved in the pathogenesis of cerebral ischemia. Previous studies have confirmed that the brain surrounding an intracerebral hematoma develops ischemia. We investigated the number and distribution of cells exhibiting DNA fragmentation with apoptotic morphology in the transient intracerebral mass lesion to determine whether apoptosis contributed to the lesion progress after intracerebral hemorrhage (ICH). Transient intracerebral mass was created by inflation of a microballoon for 10 min (group A) or 2 h (group B) in the caudoputamen in rats, and brains were examined 1, 3, 6, 24, and 48 h after microballoon deflation. The lesion volume was calculated using parallel coronal sections with cresyl violet staining. Terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine (dUTP)-biotin nick end labeling (TUNEL) was used to detect cells undergoing DNA fragmentation. Immunohistochemistry for Fas antigen was also done to ascertain molecular mechanisms of apoptosis. Histological examination of hematoxylin and eosin-stained sections showed the typical appearance of neuronal necrosis in the caudoputaminal lesion. Lesion volume in the caudoputamen gradually increased as time advanced from 1 to 48 h. Cells stained heavily by TUNEL with apoptotic morphology were detected in the lesion, but not in the inner boundary zone of the lesion. The number of these cells significantly increased from 6 to 24 h in each experimental group (p < 0.05). The cells with positive immunoreactivity for Fas antigen was prominently observed in the lesion at 6 h. The distribution of apoptotic cells and the rapid increase in the number of apoptotic cells after 24 h propose that apoptotic cell death may contribute to lesion core formation but not to gradual development of the lesion.
细胞凋亡参与了脑缺血的发病机制。先前的研究已证实，脑内血肿周围的脑组织会发生缺血。我们研究了短暂性脑内肿块病变中呈现凋亡形态的DNA片段化细胞的数量和分布，以确定细胞凋亡是否参与脑出血（ICH）后的病变进展。通过在大鼠尾壳核中用微球囊充气10分钟（A组）或2小时（B组）制造短暂性脑内肿块，在微球囊放气后1、3、6、24和48小时检查脑组织。使用甲酚紫染色的平行冠状切片计算病变体积。采用末端脱氧核苷酸转移酶（TdT）介导的脱氧尿苷（dUTP）-生物素缺口末端标记（TUNEL）法检测发生DNA片段化的细胞。还进行了Fas抗原的免疫组织化学检测以确定细胞凋亡的分子机制。苏木精和伊红染色切片的组织学检查显示尾壳核病变中有典型的神经元坏死表现。从1小时到48小时，尾壳核的病变体积随时间逐渐增加。在病变中检测到TUNEL染色呈强阳性且具有凋亡形态的细胞，但在病变的内边界区未检测到。在每个实验组中，这些细胞的数量从6小时到24小时显著增加（p<0.05）。在6小时时，在病变中显著观察到Fas抗原免疫反应阳性的细胞。凋亡细胞的分布以及24小时后凋亡细胞数量的快速增加表明，凋亡性细胞死亡可能有助于病变核心的形成，但对病变的逐渐发展没有影响。
