[Analysis of renal calcification and stone formation in rats treated with ethoxyquin using X-ray analytical scanning...

Rat renal calcification and stone formation were investigated using a JEOL-JSM840A scanning electron microscope (SEM) equipped with a LINK-QX200J energy dispersed X-ray detector (EDX). Male Wistar rats were treated with 100 ppm N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the drinking water or 10% NaCl in the diet for 8 weeks, and subsequently administered a dietary supplement of 0.1% ethoxyquin (EQ) for 32 weeks. An additional group received the EQ treatment alone. Calcification and stones were observed from the renal papilla to the pelvis region in all EQ treated groups. The incidence and grade of the lesion in the combined treated groups were much more greater than in the group treated with exposed to EQ alone. Ultrastructurally, microvilli on the surface of the renal papilla cells appeared degenerated or disappeared completely in the treated groups. Chemical element analysis of the renal stones revealed P and Ca to be the primary constituents. They were therefore considered to be of hydroxyapatite type.