[Stereologic analysis of renal cortical structures during compensatory hypertrophy in rats]

The qualitative and quantitative study of renal cortical structures was performed seven days after unilateral nephrectomy. Adult Wistar rats (10 male and 10 female) were ether-anaesthetized and the kidneys were removed by dorsolateral approach. Renal hypertrophy was determined by measurement of kidney dry mass. The samples of renal tissue were embedded in paraffin, sectioned at 6 microns and stained by azan and haematoxylineosin methods. The volume densities of renal corpuscles, the epithelium of tubules, luminal space of tubules and cortical interstitial structures were calculated using Weibel's multipurpose test system M 42. The qualitative analysis was performed to determine possible structural sex differences of cortical parenchyma during compensatory hypertrophy. There was no significant difference in volume densities of renal corpuscles and distal tubules between control and hypertrophic kidney. The volume density of the epithelium of proximal tubules and interstitial blood vessels were statistically significant increased in hypertrophic kidney compared to the values determined in control kidney. The volume density of luminal space of proximal tubules and interstitial tissues were statistically significant decreased in hypertrophy compared to control kidney. The data from present studies shows that the increase in epithelial volume of proximal tubules and interstitial blood vessels volume have the primary role in compensatory kidney enlargement after unilateral nephrectomy, while renal corpuscles do not participate significantly.