The influence of water pH on the genesis of cadmium-induced cancer in a rat model

Abstract

Cadmium is a heavy metal that is widely used in industry and can cause tumours in multiple organs. The purpose of our study was to investigate the effect of water pH in the genesis of cadmium-induced cancer. We divided 98 male Wistar rats into 7 groups: group A - 15 rats that received cadmium chloride (CdCl 2 – 400 mg/L) in their drinking water at a neutral pH of 7.0; group B - 15 rats that received CdCl 2 (400 mg/L) in their drinking water at an acidic pH of 5.0; group C - 15 rats that received CdCl 2 (400 mg/L) in their drinking water at a basic pH of 8.0; group D - 15 rats that received water at an acidic pH of 5.0; group E - 15 rats that received water at a basic pH of 8.0; group F - 15 rats that received water at a neutral pH of 7.0; and group G - 8 rats that were subcutaneously injected with a single dose of cyclophosphamide (50 mg/kg). Groups A through F were euthanised 6 months after the start of the experiment and group G was euthanised 24 hours after cyclophosphamide injection. We collected the liver, kidneys, pancreas, prostate, seminal vesicles and testes for histopathological analysis and the bone marrow for micronuclei testing. In all of the groups, neither neoplastic lesions nor an increase in micronuclei (p>0.05) were observed in the liver, kidney, pancreas, seminal vesicles and testes. We found that animals exposed to cadmium had grade one prostatic intraepithelial neoplasia, but this was found more frequently in animals from group B (p<0.05). The acidic pH increased the formation of pre-neoplastic lesions in the prostate glands of cadmium-exposed animals.