Urinary scandium as predictor of exposure: effects of scandium chloride hexahydrate on renal function in rats

Some of the rare earth elements such as Sc are believed to be non-toxic and, at present, are widely utilized for the replacement of toxic heavy metals in technological applications, but they are not entirely free of toxicity, with hidden potential health risks. In this animal experiment, we report the urinary scandium (Sc) excretion rate and nephrotoxiciy in male Wistar rats. For this purpose, the rats were given a single dose of a solution of scandium chloride by intraperitoneal injection. The Sc excretion (U-Sc) was determined in 24-h urine samples by inductively coupled plasma-argon emission spectrometry along with the Sc nephrotoxicity, urine volume (UV), creatinine (Crt), beta-2-microglobulin (beta2-MG) and N-acetyl-beta-D-glucosaminidase (NAG). A dose-dependent Sc excretion of 0.0063% (r = 0.97) via 24-h urine was confirmed. The administration of Sc induced a significant decrease of UV and Crt and a significant increase of NAG and beta2-MG. These results suggest that U-Sc can be a useful tool for monitoring Sc exposure. The formation of Sc colloidal conjugates that deposit in glomeruli may be the cause of a reduction of the glomerular filtration rate. We propose that the analytical method and results described in this study will be of great importance for future toxicological studies on Sc exposure.