The oxidative DNA base damage in testes of rats after intraperitoneal cadmium injection

Cadmium is known to be a carcinogenic metal that especially its compounds have sufficient evidence in both humans and experimental animals beneath its environmental effects. Testis tissue is highly sensitive to the effects of cadmium. It is proposed that cadmium also increases oxygen derived free radicals and lipid peroxidation. As indicators of oxidative DNA damage, 6 oxidative DNA bases were determined by using Gas Chromatography/Mass Spectrometry-Selected Ion Monitoring technique. 45 Sprague-Dawley rats (225-300 g) were used as experimental animals and were divided into 3 groups of 15 rats. A single 2 mg NaCl/kg body wt, 0,5 and 1,25 mg CdCl2/kg body wt were injected intraperitoneally to control, low and high dose groups, respectively. 5-OH Cytosine, 8-OH Adenine and Fapy Guanine lesions were elevated significantly in high dose group in the first day. A clear dose-response relationship was seen between dose groups and 8-OH Adenine levels related with time in all periods. There was a significant dose-response relationship in 2-OH Adenine, Fapy Guanine and 8-OH Guanine, especially in the second week suggesting the inhibition of XPA protein by cadmium after first week. In contrast, the observation of a significant decrease of 5-OH Cytosine levels after first week showed that cadmium could not affect the enzymes repairing the cytosine base lesions.