Efeito da L-glutamina na morfologia glomerular de ratos portadores de tumor de Walker-256

Abstract

Cancer-related cachexia leads to metabolic changes leading to increased oxidative stress and inflammation that may promote morphological and physiological changes in different organs. This work aimed to describe morphologically the glomerular changes due to cachexia and the effect of supplementation with L-glutamine (2%) on renal protection. Twenty male Wistar rats were used, distributed in four groups: control (C); tumor carriers of Walker-256 (TW); control supplemented with 2% L-glutamine (CG) and Walker-256 tumor carriers supplemented with 2% L-glutamine (TWG). The results demonstrated a reduction of the glomerular density in the TW group and a decrease in the glomerular loss in TWG. There was an increase in the area of the glomerular tuft and reduction of the urinary space in TW. The area of the glomerular mesangium was larger in the TW and TWG than in the C groups, but TWG was smaller than TW. The percentage of the area occupied by extracellular matrix in the glomerular tuft was higher in TW and TWG. The glomerular area occupied by collagen was higher in TW and TWG, but it was lower in the treated group. FGF-2 expression was higher in the TW group, whereas TWG showed the lowest immunolabelling of all groups. The data indicate that the cachexia in the kidney changes the glomerular morphology with loss of glomeruli and glomerular fibrosis. Such changes can lead to functional renal impairment compromising renal filtration and levels of eliminated substances, which serve as indicators for drug dose adequacy and for treatment. On the other hand, supplementation with L-glutamine improves most of the analyzed parameters, minimizing the effects of cachexia in the treated animals, especially glomerular density and renal fibrosis, justifying its use in the treatment of cancer patients.