Tetracyclines and lead metabolism in rats.

The effects of oral, parenteral pretreatment, and posttreatment with tetracyclines on lead metabolism were studied in 7 to 9 week-old female rats. In animals receiving different doses of tetracyclines orally (30 to 600 mg/kg daily) for 12 days the retention of an oral dose of 203Pb applied on the 4th day of the treatment was, at the end of the experiment, the same as in the controls. In animals receiving daily intraperitoneal doses of tetracycline (18.8 to 75 mg/kg for 12 days) the retention of an intraperitoneal dose of 203Pb applied on the 4th day of treatment was, at the end of the experiment, the same or higher than in the untreated group. This indicates that tetracyclines are not likely to be useful in the prevention or treatment of lead poisoning.