INFLUENCE OF ENVIRONMENTAL LEAD ON MEMBRANE ION-TRANSPORT IN A FRENCH URBAN MALE-POPULATION

Red cell cation transports (Na+{single bond}K+ pump, Na+{single bond}K+ cotransport system, Na+{single bond}Li+ countertransport, and Na+ and K+ passive permeabilities) and blood and hair lead levels were measured in 129 healthy adult Caucasians not occupationally exposed to lead. In agreement with previously reported in vitro results showing a lead-induced Na+{single bond}K+ ATPase inhibition, Na+{single bond}K+ pump activity was inversely correlated with hair lead (r = -0.18, P < 0.05); it was not significantly correlated with blood lead. Na+{single bond}K+ cotransport activity was inversely correlated with blood lead contents (r = -0.23, P < 0.05) but not with hair lead. No significant correlation was found between the remaining cation transport pathways and lead levels. It is hypothesized that environmental, long-term exposure to lead may result in pump inhibition, while a recent exposition to lead may result in inhibition of the Na+{single bond}K+ cotransport system. Further research is required in order to determine if red cell Na+{single bond}K+ pump and Na+{single bond}K+ cotransport activities are sensitive indicators of chronic and recent exposures to lead, respectively. © 1990 Academic Press, Inc. All rights reserved.