Histochemical and histological effects of lead on the liver and kidney of the dog.

In a series of 3 experiments, beagle dogs were dosed orally with lead carbonate and the histochemical and histological changes in the liver and kidney assessed. Dosing at 50 mg/kg per day for 5 weeks resulted in well documented histological changes in the kidney and hydropic degeneration in the liver; significant alterations in the activity of the majority of enzymes studied were also seen in both organs. In dogs dosed for one week at 50 or 100 mg/kg no histological changes were seen and histochemical alterations were mainly confined to the dehydrogenases and NADPH diaphorase. A third group of dogs were dosed for 3 weeks; during a subsequent recovery period of almost 2 months the mild clinical effects produced by lead during the dosing period were quickly reversible except in 2 dogs. At the end of the recovery period histochemical alterations were evident in both organs of these 2 dogs principally shown by a reduction in the dehydrogenases of the liver. The findings are interpreted as an effect by lead on a range of cellular enzymes particularly those involved in energy production, these effects being still demonstrable after an extended recovery period.