title: Effects of divalent cations on calcium levels, aggregation and morphology of human blood platelets in vitro.
abstract: Some effects of cadmium, nickel, strontium and manganese ions upon human platelets in vitro are reported. Both Mn and Cd induced aggregation, Mn being the most effective. Ni and Sr did not have this effect. Scanning electron microscopic observation showed that Mn and Cd, but not Ni and Sr induced shape changes in the platelets. X-ray microanalysis of pyroantimonate fixed platelets revealed that calcium was displaced from both membrane and cytoplasmic regions by all four cations. The magnitude of displacement occurred in the sequence Mn > Cd > Ni approximately or equal to Sr. Manganese was detected both in the cytoplasm and membrane region of those platelets treated with this ion. It is suggested that the cations are influencing directly certain macromolecular ligands whose condition controls platelet surface properties.
mesh_terms: D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D002104:Cadmium / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002413:Cations, Divalent / Q000494:pharmacology*; D006801:Humans; D008345:Manganese / Q000494:pharmacology; D009532:Nickel / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D013324:Strontium / Q000494:pharmacology
chemical_list: D002413:Cations, Divalent; D002104:Cadmium; D008345:Manganese; D009532:Nickel; D002118:Calcium; D013324:Strontium