花背蟾蜍蝌蚪发生类坏死的皮肤在恢复过程中的超微结构

本实验以花背蟾蜍后肢芽期的蝌蚪为材料,用0.001 mol/L氨水(氨水组)和0.01mol/L醋酸(醋酸组)处理皮肤使之发生类坏死。以细胞核、细胞表面、细胞质及细胞间隙等的超微结构变化为指标,研究了各组皮肤发生类坏死后恢复过程中的可逆变化。结果观察到:两组均能引起核染色质浓缩,粘液分泌,液泡增多,线粒体及内质网膨大变形,细胞间隙变窄;醋酸还引起张力原纤维的凝集及紊乱等。恢复过程中,细胞核内染色质的分布趋于均匀,粘液的分泌渐正常,液泡减少,线粒体及内质网的形态逐步恢复,但细胞间隙一直很??窄;醋酸组中张力原纤维恢复成束且排列较整齐。作者认为氨水及醋酸引起蝌蚪皮肤发生类坏死后,在一定时间内是可以恢复的,而且此可逆变化也反映在超微结构的变化上。

THE ULTRASTRUCTURE OF TADPOLE PARANECROTIC SKIN DURING ITS RECOVERING PROCESS

The tadpole of Bufo raddei with hindlimb buds was used in the experiment.Paranecro- sis was caused by 0.001 N ammonia water or 0.01 N acetic acid.The ultrastructural changes during the recovering process after paranecrosis were observed.In the case of paranecrosis,a series of changes occurred in the epidermal cells,i.e.,most of the chroma- tin accumulated close to nuclear membrane in the nuclei,excretion of mucus,increase of cytoplasmic vesicles,swollen endoplasmic re- ticula and mitochondria with low electron density and disordered cristae,narrowing of intercellular space.The tonofilaments in the epidermal cells treated with acetic acid became aggregated and disordered.During the recover- ing process,the chromatin in the nuclei ten- ded to be distributed uniformly,the secretion of mucus became gradually normal,decrease of cytoplasmic vesicles,the mitochondria re- covered to its normal shape with high elec- tron density,the endoplasmic reticula more or less returned to its ordinary figures,the to- nofilaments were disaggregated and arranged regularly,but the intercellular spaces remain- ed narrow.The paranecrotic skin is consi- dered to be able to recover to normal condi- tion under given period,and all of the chan- ges during the recovering process may be demonstrated on the ultrastructures.