Cyclic AMP opposes IP3-induced calcium release from permeabilized human platelets.
Platelets permeabilized by means of a high voltage electric field demonstrated time- and ATP-dependent uptake of 45Ca++. Submicromolar concentrations of inositol-1,4,5-trisphosphate (IP3) caused a rapid release of 45Ca++ which was followed by a slower reuptake. Adenosine 3':5'-cyclic monophosphate (cAMP) did not affect 45Ca++ uptake but did reduce IP3-mediated calcium release in a concentration-dependent manner over the range of 1-100 microM. Because cAMP concentrations in this range occur following exposure of platelets to prostacyclin and other agents which interfere with platelet function, it is proposed that cAMP-mediated inhibition of the action of IP3 may play a role in the antithrombotic activity of compounds believed to elevate levels of this cyclic nucleotide.
Moos
M
M
Department of Biochemistry, Medical School, University of Minnesota, Minneapolis 55455.
Goldberg
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ND
D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000097:blood*; D002463:Cell Membrane Permeability; D000242:Cyclic AMP / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000494:pharmacology*; D013403:Sugar Phosphates / Q000494:pharmacology*
D007295:Inositol Phosphates; D013403:Sugar Phosphates; D015544:Inositol 1,4,5-Trisphosphate; D000242:Cyclic AMP; D002118:Calcium