title: Combined effects of lead and EDTA on Na+,K+-ATPase activity of erythrocyte membranes.
abstract: Erythrocyte Na+,K+-ATPase activity increased significantly in lead workers of a lead refining factory when measured with EDTA and compared to the controls without EDTA. The enzyme activity measured with EDTA increased in the following order: controls less than office workers in a lead refining factory less than lead workers. A positive correlation existed between blood lead and enzyme activity with EDTA (r = 0.380, p less than 0.10), and the activity without EDTA (r = 0.398, p less than 0.05). A negative correlation was found between sodium in erythrocytes and enzyme activity with EDTA (r = -0.437, p less than 0.05), and the activity without EDTA (r = -0.416). But no relationship was observed between enzyme activities and potassium in erythrocytes. A positive correlation between enzyme activity with EDTA and that without EDTA was observed (r = 0.452, p less than 0.05). With addition of lead to fragments of erythrocyte membranes, a significant decrease occurred in the activity of the enzyme without EDTA, whereas no change was observed with EDTA. No significant change occurred in the enzyme activity with and without EDTA upon addition of lead to blood. The maximum level of lead in membrane fragments (lead combined with membranes) of workers exposed to lead was 0.60 microgram/mg protein, and that in the experiment of addition to blood was 7.0 micrograms/mg protein.
mesh_terms: D000328:Adult; D004492:Edetic Acid / Q000494:pharmacology*; D004781:Environmental Exposure; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D066298:In Vitro Techniques; D007854:Lead / Q000097:blood / Q000633:toxicity*; D008297:Male; D008875:Middle Aged; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood*
chemical_list: D007854:Lead; D004492:Edetic Acid; D000254:Sodium-Potassium-Exchanging ATPase