Simplified Stereological Evaluation of Renal Morphology after Unilateral Ureteral Obstruction

Objective and methods: This study established a simple stereological method to obtain quantitative information about two- or three-dimensional structures based on observations from kidney sections in the unilateral ureteral obstruction(UUO) model. Results: Tubulointerstitial area(TA) and TA/the area of a rectangular field(RA) were raised gradually, but significantly, in the obstructed kidney from 1 to 3months post-ligation in comparison to the sham kidney of sham-operated rats(SOR). On the contrary, glomerular area(GA) and glomerular volume(GV) were decreased progressively over time, but significantly, in the obstructed kidney from 3weeks to 3months post-ligation compared to the sham kidney of SOR. UUO caused a progressive decline of TA and TA/RA in the contralateral kidney. More specifically, there were significant decreases in TA at 1,2,3months post-ligation, while in TA/RA only at 3months post-ligation in comparison to the right kidney of SOR. In contrast, GA and GV enhanced in a time-dependent manner in the contralateral kidney, in which the difference in GA reached significance only at 3months post-ligation, whereas the difference in GV reached significance from 1 to 3months post-ligation when comparing with the right kidney of SOR. Conclusions: Our results confirmed two typical features of obstructive nephropathy, including widen interstitial space and glomerular atrophy in the obstructed kidney, and compensatory growth of the contralateral kidney.