Moreover, these metals might in?uence the enzymatic anti-oxidant system indirectly via disorders else in the body status and depletion of bioelements necessary for proper function of these enzymes such as selenium (Se), zinc (Zn), copper (Cu), manganese (Mn) and iron (Fe). GPx is a Se-dependent enzyme; CAT contains Fe in its active centre, whereas SOD activity is dependent on Zn, Cu and Mn.[8] Most of the studies were carried out following exposure to a single metal and some studies on co-exposure to Pb and Cd showed that these metals had additive effects on anti-oxidants system in the biological system.[9] N-acetyl L-cysteine (NAC), a potent anti-oxidant, is a sulfur-based amino acid needed to make reduced glutathione (GSH), a natural non-enzymatic anti-oxidant produced in the body to fight free-radical activity.
It is being employed clinically for the treatment of many diseases. It is an excellent scavenger of free radicals and has been also used as a chelator of heavy metals to protect against oxidative stress and prevent damage to cells.[10,11] Therefore, the present study was undertaken to explore the toxicodynamic interaction of Pb with Cd and to evaluate the protective role of NAC in rats. MATERIALS AND METHODS Chemical reagents Lead acetate, Cadmium chloride and all other chemicals used in our experiments were purchased from SRL Pvt. Ltd., Mumbai. Animals Male Albino rats of Wistar strain weighing about 200-250 g were procured from National Institute of Nutrition, Hyderabad, Andhra Pradesh. The animals used in this study were approved by Committee for the Purpose of Control and Supervision of Experiments on Animals (approval no.
5/I/10/2010). Experimental design The study was carried out on 48 male Wistar rats randomly divided into 8 groups with six rats in each group. All the groups were maintained as per the following schedule for 3 months. Group 1: Normal control. Group 2: N-acetyl-L-cysteine (NAC) @ 300 mg/kg body weight. Group 3: Lead toxic control (lead acetate @ 1000 ppm in feed). Group 4: Cadmium toxic control (cadmium chloride @ 300 ppm in feed). Group 5: Lead and cadmium toxic control @1000 and 300 ppm, respectively, in feed. Group 6: Lead and NAC, respectively @ 1000 ppm in feed and @ 300 mg/kg body weight. Group 7: Cadmium and NAC, respectively @ 300 ppm in feed and @ 300 mg/kg body weight.
Group 8: Lead, cadmium and NAC, respectively @1000, 300 ppm in feed and @ 300 mg/kg body weight. Lead and cadmium were used in the form of lead acetate and cadmium chloride given in the form of mash feed, NAC administered by oral gavage by diluting in the distilled Entinostat water. Biochemical assays Rat testis tissues were collected at the end of 3rd month. Rats were fasted overnight and sacrificed by cervical decapitation; testes were removed, dissected out, weighted, and washed in ice-cold saline.