The effects of BAL on the metabolism of lead and on the symptomatology in lead intoxication.

The effects of injection of BAL on the metabolism of lead has been studied by Eagle (1948) and by Ginsburg and Weatherall (1948) in animals poisoned with lead acetate, and by Ryder, Cholak, and Kehoe (1947) in human cases of acute lead poisoning. The action ofBAL has been shown to be the same both in experimental animals and in man; in animals it had no demonstrably protective action, and on occasion appeared to accelerate the toxic effects of lead acetate in rabbits; similarly in man, three days' treatment with 1-7 g. of BAL was without beneficial effect. Characteristic effects were observed on the metabolism of lead, inasmuch as there followed a rapid drop in the lead concentration in the red blood cells, and an immediate rise in urinary lead concentration, to a degree far greater than that observed from any other kind of treatment. The plasma and faecal lead concentration were unchanged by BAL treatment. Eagle (1948) advised caution in the use of BAL, although he did not see evidence in man of toxic effects in cases of lead poisoning. He recommended four-hourly injections of 2-5 mg. per kg. body weight repeated four times a day and continued for two to four days, diminishing thereafter gradually to about two injections a day. Ginsburg and Weatherall (1948) used the Th. 3 isotope of lead to study lead acetate distribution in tissues. Administration of lead acetate was followed by 50 mg. per kg. BAL up to 23 hours later. This resulted in increased urinary excretion of lead and a shift in the tissue distribution from the liver, the spleen, the red cells, and the bone marrow to the skeletal and cardiac muscle. Our studies on BAL treatment in human cases of lead intoxication were started two years before read-