activation of cellular protein kinases under these conditions was not accompanied by the formation of inositol phosphates and was found to strictly depend upon extracellular ca2+ , suggesting that the platelet 's secretory response to the c5b-9 proteins is triggered directly by the influx of ca2+ across the plasma membrane . measurement of intracellular ca2+ confirmed that elevation of this ion in the cytosol was strictly dependent upon increased plasma membrane permeability due to c5b-9 assembly and was not accompanied by mobilization of this ion from internal storage pools .
C0007634
cellular
C0007603
plasma membrane