Quantitative changes in the testicular structure in mice exposed to low doses of cadmium

The purpose of this study was to quantify the consequences of a long-term exposure to low doses of cadmium on the testicular structure. Sexually mature male mice were orally exposed to cadmium (0.015 g/1 of CdCl2 in drinking water) for 1, 3, 6 and 12 months and then sacrificed; cadmium withdrawal was also considered in two groups raised with cadmium for 3 and 6 months, and without cadmium for 3 and 6 months before sacrifice, respectively. Morphometrical and stereological estimations were applied to quantify the structural constituents of the testes. The morphological parameters (testicular mass and size) were significantly decreased at 6 and 12 months of cadmium exposure. Interstitium was the testicular constituent most sensitive to cadmium so that significant decreases in the volume fractions of interstitium and Leydig cells were recorded as from 3 months of cadmium exposure. Cadmium-exposed seminipherous tubules showed increased diameters and lumens together with decreased tubular densities and epithelial percentages.