HISTOCHEMICAL AND MORPHOMETRIC ANALYSIS OF CONNECTIVE TISSUE IN HUMAN GLOMERULES DURING AGING

Abstract

During aging there are alterations in human glomerules followed by increase of the connective tissue amount, accumulation of glomerular basal membrane and mesangial matrix on account of the rest of cell population. The aim of the study was quantification of the present connective tissue in mesangium of glomerules which morphologically did not show signs of sclerosis and determination of its part in glomerular structure. Investigation included 30 tissue samples of human kidneys of cadavers of both sexes, aged 20-85. Tissue samples were routinely stained with Mallory trichrome stain and analyzed by light microscope under 400´ magnifications. Images were analyzed with ImageJ software. Statistical analysis was performed with NCSS-PASS software. Cluster analysis was performed for the classification of glomeruli into 3 age groups, first with average age of 29, second with 44 and third with average of 71 years old. Histochemical investigations indicated the growth of connective tissue in mesangium of human glomerules during aging. It was also demonstrated morphometrically showing significant increase (p<0.05) of mean connective tissue area and its percentage in glomerule. In first, the youngest group the connective tissue was present in 17.33%, while in second group there was statistically significant increase (32.11%). The most significant growth compared to other age groups appeared in third group, where there was 40.66% of connective tissue in glomerule. Results of morphometrical and statistical analysis suggest that during aging process there is significant increase of area and percentage of connective tissue in the glomerule followed by reduction of cell size