Stereologic estimates of glomerular volume in unilaterally nephrectomized rats

OBJECTIVE: To quantitatively evaluate the changes in glomeruli in unilatera lly nephrectomized adult rats by unbiased stereologic techniques. STUDY DESIGN: Adult rats received unilateral nephrectomy (UN) or a sham ope ration. Four weeks later the remnant kidneys were fixed and sampled by the fractionator method. Consecutive sections were prepared and stained. Morpho metric analyses were performed by a light microscope equipped with computer -assisted digitizer. RESULTS: The total glomerular volume increased by 51% (P < .01). The volume density of glomeruli did not change (5.58 +/- 0.22 x 10(-2) US. 5.51 +/- 0 .44 x 10(-2), P > .50). In contrast, the numerical densities of glomeruli d ecreased by 36% (P < .05). CONCLUSION Glomerular enlargement, but not the increase in glomerular numbe r, contributed heavily to compensatory glomerular growth after UN in rats.