Disector方法观察一侧肾切除成年大鼠留存肾肾小球形态计量学改变

Stereological study on glomerular volume in unilaterally nephrectomized adult rats

应用Disector方法研究一例肾切除成年大鼠留存肾肾小球的形态计量学改变。结果表明,成年SD大鼠行一侧肾切除术后四周,留存肾（右）肾小球平均体积较假手术对照组（右肾）增加43％（分别为6.49±1.15×10~5μm^3,4.55±1.00×10~5 μm^3,P<0.05）全肾体积增加49％（P<0.01）,肾小球体密度没有改变（分别为5.58±0.22×10^（-2）,5.51±0.44×10^（-2）,P=0.7790）;肾小球数密度较正常对照组减少36％（分别为79.9±13.3mm^(-3),125.6±28.2mm^(-3),P<O.05）,全肾（右）肾小球总数没有改变（2.55±0.33×10~4,2.53±0.45×10~4,P=0.9500）。提示成年及成年以后肾切除,留存肾肾小球功能的代偿主要依赖于体积增大以增加滤过面积,肾小球平均体积与全肾体积增加相仿,肾小球的代偿性生长不包括肾小球数量的增加。

In this study, Disector, one of stereological methods, was used to determine the growth of glomeruli after unilateral nephrectomy(UN) in adult SD rats. The weight of remaining kidney increased by 49% four weeks after UN. Morphometric analysis of glomeruli showed that the mean glomerular size in UN rats(n = 4) increased by 43% as compered to the controls(n = 4) (6.49±1. 15×105 vs. 4. 55±1. 00×105 μm3, P<0. 05, mean±SD). The total glomerular volume increased by 51% (P<0. 01). While the volume density of glomeruli remained unchanged (5. 58±0. 22×10-2 vs. 5. 51±0. 44×10-2, P>0. 50). On the contrary, the numerical densities of glomeruli were 79. 9±13. 3 mm-3 in UN rats and 125. 6±28. 2 mm-3 in the control (-36%, P <0. 05), implying that little or no increase in glomerular number had occurred. The results show that the enlargement of glomerular size rather than the increase of glomerular number made the main contribution to the compensatory gomerular growth in UN adults, and that the compensatory proliferative changes of glomeruli were not as prominent as that of other components (such as tubules). These findings are consistent with those seen in our previous autoradiographic studies. The stereological method used in this study could serve as a means of quantitative description providing objective, unbiased and reproducible data in other morphometric studies as well.