Protective effects of chromium on the toxicity of cadmium in vivo

The acute toxicity of cadmium is known to be less in animals pretreated with zinc. However, the ability of other metals to decrease the toxicity of cadmium has not been thoroughly examined. Therefore, the present study was designed to determine if chromium will decrease the acute toxicity of cadmium. Rats received one of the following treatments: (1) saline, saline; (2) saline, cadmium; (3) chromium, cadmium; (4) zinc, cadmium; and (5) chromium, saline. The first of each treatment pair was administered i.p. 36 h and 12 h prior to the second of the pair, which was given i.v. The dose of chromic and zinc chloride was 100 mumol/kg and that for cadmium was 9 mumol/kg except for the lethality study in which 35 mumol/kg was used. Chromium decreased the number of animals that died from cadmium. Furthermore, testicular atrophy due to cadmium was also prevented by pretreatment with chromium. However, chromium did not block the cadmium-induced decrease in hepatic microsomal metabolism as evidenced by a fall in both cytochrome P-450 and aniline metabolism. The observed effects of chromium were not due to an alteration in cadmium distribution. This study demonstrates that chromium can reduce some of the acute toxic effects of cadmium and re-emphasizes the requirement for knowledge not only of individual metals but also for the interactions among such chemicals.