Effectiveness of copper chloride in protecting against alterations induced by mercury chloride in newborn rats

This work investigated the effects of copper as preventive treatment against mercury-induced alterations in young rats. Wistar rats were treated (subcutaneous) with saline or CuCl(2) · 2H(2) O (6.9 mg/kg/day) from 3 to 7 days old and with saline or HgCl(2) (5.0 mg/kg/day) from 8 to 12 days old. Rats were sacrificed 24 h after the last dose. Mercury-exposed rats presented inhibition of liver (43%) and kidney (52%) porphobilinogen (PBG)-synthase activity and serum lactic dehydrogenase activity (50%). Also, an increase of the serum creatinine and urea levels around threefold and fivefold was observed, respectively. Pre-exposure to copper partially prevented the mercury effect on liver but not on kidney PBG synthase, and prevented the increase of the creatinine levels. Blood and brain PBG synthase and serum alanineaminotransferase activities, as well as glycemia, and liver glycogen content were not altered by treatments. These results show that copper, although being an essential metal, is inefficient as a preventive agent against mercury poisoning in parameters investigated after the end of mercury exposure.