Ca2+ ionophores and the activation of human blood platelets. The effects of ionomycin, beauvericin, lysocellin, virginiamycin S, lasalocid-derivatives and McN 4308.
Platelet activation is linked to an increase in the cytoplasmic Ca2+ concentration and consequently can also be induced by ionophores which mobilize Ca2+ from intracellular storage sites or transport it through the plasma membrane. The ionophores mostly used in studies on platelet activation are A 23187 and lasalocid (X-537A). The effects of eight compounds with known Ca2+-ionophoric activity in synthetic or natural membrane systems were studied in order to investigate the relationship between transport Ca2+ and activation of platelets. Inomycin acts as a true Ca2+ ionophore: it elicits rapid shape change, aggregation, the release reaction (secretion) and clot retraction (contraction). Beauvericin activates platelets too, but probably not by increasing the cytoplasmic Ca2+ concentration. Lysocellin does not activate platelets but induces a passive loss of serotonin.
D000900:Anti-Bacterial Agents; D001692:Biological Transport / Q000187:drug effects; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D002118:Calcium / Q000097:blood*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D047630:Depsipeptides; D004987:Ethers / Q000494:pharmacology; D006801:Humans; D015759:Ionomycin; D007476:Ionophores / Q000494:pharmacology*; D007700:Kinetics; D007832:Lasalocid / Q000494:pharmacology*; D010455:Peptides; D010456:Peptides, Cyclic / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects; D014769:Virginiamycin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D047630:Depsipeptides; D004987:Ethers; D007476:Ionophores; D010455:Peptides; D010456:Peptides, Cyclic; D010880:Piperidines; D014769:Virginiamycin; C004456:beauvericin; D015759:Ionomycin; C025959:McN 4308; D002118:Calcium; D007832:Lasalocid