Abstract
Some disturbance in the conversion of delta-aminolevulinic acid to coproporphy-rin in the kidney of lead poisoned rabbits was examined. The supernatant of homogenate of the liver and the kidney and of hemolysates of red blood and bone marrow cells from lead poisoned rabbits were incubated with delta-aminolevulinic acid to estimate porphobilinogen and porphyrins synthesized. Coproporphyrin isomers were also analysed. Porphyrins were found to be produced in larger amount by the kidney from poisoned animals than from control ones, and to the greatest degree by the hemolysates. Coproporphyrin was produced about two times as much in the kidney of poisoned animals as in that of control. Coproporphyrin produced was identified to be largely of type I in the liver and of type III in red blood and bone marrow cells. It seems that while the kidney plays a certain role in increased urinary excretion of type I coproporphyrin, urinary coproporphyrin is mostly of erythropoietic origin in lead poisoning.
