Association between peri-glomerular As-Cu accumulation and physiological and histological alterations in rat kidney

PEREZ, R.D; RUBATO BIRRI, P.N.; CREMONEZZI, D.; PEREZ, C.A.; RUBIO M.; BONGIOVANNI G.

Valencia, España

Congreso; 2nd International Congress. Arsenic in the Environment. Arsenic from nature to humans; 2007

Universidad de Valencia

Arsenic (As) is one of the most abundant hazards in the environment and it is a human carcinogen. Prolonged ingestion of arsenic contaminated water may result in the manifestations of toxicity in practically all systems of the body (hydroarsenicism). Previous studies carried out by X-ray fluorescence spectrometry using synchrotron radiation (SR-μXRF) showed a high concentration of As in renal cortex from chronically exposed rats during 60 days. This accumulation was accompanied by an important increase in the Cu concentration. The present study focused on the relationship between As and Cu distribution and concentration along renal cortex and the nephrotoxicologial process in arsenic chronically exposed rats. Experiments were done on 12 male Wistar rats, divided into tree experimental groups. As60 and As120 groups received sodium arsenite at a dose of 100 μg/ml by drinking water during 60 and 120 consecutive days, respectively. Control or Ctrol group received As-free water (by XRF). For histological analysis, 5 μm thick sections were stained with hematoxylin and eosin (HE). Biochemical analyses were used to determine concentrations of plasmatic urea and creatinine. The As and Cu mapping were carried out by X-Ray Fluorescence Spectrometry (SR-µXRF) using a collimated white synchrotron spectrum (300 μm) on kidney slices (1 mm thick) showed As and Cu co-distribution in renal cortex. Then, 0.5 x 0.5 mm sections in renal cortical slices (100 μm thick) were scanned with a micro-collimated white synchrotron spectrum (30 μm) and the elemental distribution was determined by X-Ray Fluorescence Spectrometry (SR-µXRF). The results shown a peri-glomerular accumulation of As and Cu. The deleterious effects of arsenic consumption may also be seen by a decreased Bowman´s space as well as a decreased plasmatic creatinine and BUN values at 60 days of treatment. While tubular injury was seen at 120 days of exposition. Since metal accumulation, even essential ones, may therefore be critical for that organ, this study supports the hypothesis that the accumulation of As and Cu in peri-glomarular zone may to have some bearing on the early stage of the arsenic-associated nephrotoxicologial process.