低剂量γ射线照射孕鼠胎脑中异常结节样结构

用低剂量γ射线照射受孕13天的大鼠后,在光镜和电镜下检查胎龄为20天的胎鼠脑组织,发现其前脑腹侧部失去了正常细胞分层排列的特征,并出现许多异常的结节样细胞团。在电镜下观察到,聚成这种结节样小团的细胞形态为多形性;细胞核极不规则,核内染色质分布不匀,常聚成粗粒状或片块状;有许多细胞核呈现不同程度的核固缩变化。

ABNORMAL NODULAR CELL MASSES INDUCED BY LOW DOSE GAMMA RADIATION IN THE BRAIN OF FETAL RAT

Pregnant rats were exposed to low dose gamma radiation on day 13 of gestation, and then killedon 20th day after conception. The brains of the fetal rats were examined. Under light microscope, theventral portion of the forebrain including subiculum, amygdaloid nucleus complex and olfactory bulb,ets., showed most striking changes. Many cells in these regions had aggregated into a lot of round-sha-ped cell clusters which ws termed "abnormal nodular cell masses"(ANCM). Under electron microscope,the central space of each ANCM was filled with cytoplasm-like matrix. The shapes of the cells andtheir nuclei in the ANCM varied markedly. Some cells appeared karyopyknotic, and some had eccentricnuclei with the chromatin concentrated into granules or patches scattered unevenly in the nuclear matr-ix. In control material, the nuclear shapes were regular and their chromatin distributed evenly.