Effect of Pb++ on Fe+++ tissue concentrations and delta-aminolaevulinic acid dehydratase activity in Lumbricus terrestris.

Iron was found at the highest concentration in the chloragogenous tissue with smaller amounts in the intestine and the lowest concentration in the body wall. Earthworms treated with Pb++ for 20 days showed a decrease in the concentration of Fe+++ in the intestinal tissue but no significant changes in the other tissue. The enzyme delta-aminolaevulinic acid dehydratase (ALAD) was not detected in isolated chloragosomes but it was found in the chloragocyte cytosol, body wall and intestine. L. terrestris treated with Pb++ showed a decrease in the activity of ALAD in all tissues where it was located and particularly in the chloragocyte cytosol.