大鼠肾切除术后留存肾代偿早期细胞凋亡状态和collectrin基因表达关系的研究

Correlation of apoptosis and expression of Collectrin gene in the early stage of compensatory renal growth following uninephrectomy in the young and old rats

目的探讨调控脏器形态稳定的重要因素—细胞凋亡和新基因Collectrin在肾代偿性生长中的作用。方法用荧光染色、DNA梯度电泳分析、原位DNA片段末端标记等凋亡检测的手段,RT-PCR、免疫组织化学等Collectrin基因表达研究手段系统研究青、老年大鼠正常肾及代偿肾内细胞凋亡情况及Collectrin基因表达的差异。结果青年正常肾无细胞凋亡表现,而老年正常肾皮、髓质小管均有细胞凋亡存在,且皮质凋亡水平高于髓质;青年肾代偿3d时细胞凋亡明显增加,且髓质高于皮质,老年肾代偿3d时,留存肾细胞凋亡水平明显降低,且以皮质降低更为明显。这些过程都伴随着Collectrin基因表达的同步变化。结论凋亡是肾代偿性生长形态学改变的重要组成部分,肾代偿性生长的年龄差异与细胞凋亡有关,同时也和Collectrin基因的表达有关。

Objective To investigate the role of apoptosis, one of the major factor to maintain homeostasis of cell number of organs, in the early process of compensatory renal growth, which have been considered to including cellular hyperplasia and hypertrophy, following uninephrectomy. Methods DNA fragment gelelectrophoresis, tissue sections photolebeling technique and in situ nick translation assay were used to analyze apoptotic cells in the compensatory and normal kidney in the young and old Wistar rats. Results Apoptosis affected normal kidney of the old group, but not the young. In the old rat＇s normal kidney, apoptosis index was higher in cortical tubules than that in the medullar tubules. In the compensatory remnant kidney, apoptosis was diminished in old rats, especially in the cortex, but increased in the young rats , especially in the medulla. Conclusion Compensatory renal growth includes cellular hypertrophy, hyperplasia and apeptosis. In the old, compensatory renal growth is mainly cellular hypertrophy and reduction of cell death. In the young, compensatory renal growth is mainly cellular hyperplasia and hypertrophy, increased apoptosis may be responsible for the elimination of excess hyperplastic renal cell.