The Role of Calcium in Intracellular Cadmium Uptake by the Lichen Peltigera membranacea

The possible role of calcium in the intracellular uptake ofcadmium by the lichen Peltigera membranacea was investigated.Even when calcium was removed from extracellular sites by potassiumpretreatment, kinetic studies failed to provide evidence insupport of added calcium being a competitive inhibitor of cadmiumuptake. Calcium and cadmium uptake responded differently tothe presence of lanthanum, vanadate or verapamil. Except forthe effect of verapamil, intracellular of cadmium mostly reflectedthe quantity of cadmium bound to extracellular exchange sites.Copyright1993, 1999 Academic Press Peltigera membranacea (Ach.) Nyl., intracellular cadmium uptake, calcium uptake inhibitors, lichen