Tissue Cd Concentrations
To determine actual Cd levels, staged testicular tissues and liver, kidney, heart, and muscle were collected from untreated controls and from animals injected with CdCl2 (5 mg/kg body weight) 3 days before death as described above (3 per group); samples were stored at -70°C until analysis. Samples (200 mg) were weighed into acid-cleaned polytet-rafluoroethylene vials and digested at 70°C in trace metal-grade concentrated nitric acid (Fisher, Pittsburgh, PA), which was then evaporated to dryness at 85°C. The residue was reconstituted in 3% nitric acid and filtered (0.45 ^M). buy cipro
Cd was assayed on a Perkin-Elmer 5100 PC Atomic Absorption Spectrophotometer with Zeeman background correction equipped with a heated graphite atomizer furnace and programmer, an electrodeless discharge lamp, and an argon purge gas (Perkin-Elmer, Norwalk, CT). A matrix modifier (0.6 mg/ml Mg and 0.4 ml/ml Pd in 0.2% nitric acid) was added to the samples to stabilize Cd during the furnace char step. The linear range was 0-11 ^g/L and the detection limit was 0.15 ^g/L. For tissues measuring > 11 ^g/L, samples were diluted 10-fold in 3% nitric acid. Certified atomic absorption Cd standards were from Perkin-Elmer. Values were expressed as ^g Cd/g tissue.