【摘要】 目的研究饥饿状态对海马细胞DNA的损伤。方法分别运用单细胞电泳(彗星实验)和缺口末端标记法(TUNEL)检测细胞核DNA单链及双链损伤,半胱天冬酶3(caspase3)活性片段免疫组化检测海马细胞caspase-3激活;结合神经元尼(氏)体染色和苏木素伊红(HE)染色了解海马神经元形态和数目变化。结果经受饥饿状态1周的动物可见海马细胞DNA单链损伤,海马各区caspase-3活性片段免疫反应阴性,但TUNEL法检测到一种具非典型凋亡特征的阳性显色;经受饥饿状态2个月的动物,DNA单链损伤持续存在,海马CA1区caspase-3活性片段免疫组化见广泛细胞浆阳性表达,海马其他区域仅有零星阳性细胞,但TUNEL检测无阳性细胞。神经元尼(氏)体染色示,饥饿状态1周和2个月海马神经元部分尼(氏)体溶解消失。HE染色示,经受饥饿状态1周和2个月的动物,海马CA1区锥体层细胞数减少(P<0.05)。结论饥饿状态可造成大白鼠海马细胞染色体DNA损伤及部分细胞死亡。更多还原

【Abstract】 Objective To investigate the nuclear DNA damage of hippocampal cells in rats by food hunger. Methods Twenty adult Wistar rats were subjected to food hunger for one week or two months. The single-cell gel electrphoresis (comet assay) was used to evaluate the single-stand breaks (SSBs) of nuclear DNA, and in situ terminal deoxynucleotidyl-transferase-mediated dUTP nick end-labeling (TUNEL) to evaluate the double-stand breaks (DSBs). The immunoreaction of hippocampal cells to the active-caspase-3 segment (P17) antibody was also detected. Hematoxylin and eosin (HE) or Nissl staining was used to learn the changes of the modality and number of hippocampal neurons in the CA1 subregion. Results SSBs were observed in the rats suffering from starvation for 1 week, TUNEL- positive cells were found with special modality. Observation by electron microscopy manifested that neuronal heterochromatin aggregated toward karyotheca. Immunopositive hippocampal cells to active-caspase-3 antibody were not seen at this time-point. For the rats subjected to starvation for two months, SSBs also occurred, but TUNEL-positive cells were disappeared. Interestingly, active-caspase-3 immunopositive cells expressed mostly in cytoplasm instead of in nuclei. HE or Nissl staining suggested a decrease in the number of neurons in CA1 subregion indicative of some neuronal death. Conclusions Food hunger lead to nuclear DNA damage and death of hippocampal cells in rats.更多还原