title: The interaction of aluminum and other metal ions with calcium-calmodulin-dependent phosphodiesterase.
abstract: In the search for the mode of action of aluminum ions in dialysis encephalopathy, their interaction with calmodulin has been assessed, and compared with those of Ca2+, Pb2+, Mn2+, Hg2+ and Cd2+. The basal and calmodulin-dependent activity of phosphodiesterase was measured in the presence of the ions, and their binding to calmodulin was assessed by competition with 45Ca2+ in flow dialysis. Al3+, Mn2+, Hg2+, and Cd2+ cannot be regarded as exclusive calmodulin antagonists or agonists, but rather interact with the phosphodiesterase itself. Pb2+ however, mimicks Ca2+ in every system tested, and is active in the same concentration range as Ca2+. Our results indicate that the assumed role of Al3+ ions in dialysis encephalopathy or other neurological disturbances is not linked with calmodulin.
mesh_terms: D000535:Aluminum / Q000097:blood / Q000633:toxicity; D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002417:Cattle; D002746:Chlorpromazine / Q000494:pharmacology; D003956:Dialysis; D066298:In Vitro Techniques; D008670:Metals / Q000494:pharmacology*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*
chemical_list: D002147:Calmodulin; D008670:Metals; D000535:Aluminum; D010727:Phosphoric Diester Hydrolases; D002118:Calcium; D002746:Chlorpromazine