treatment of cells for 3 min at 37 degrees c with dibutyryl camp , a membrane-permeable analogue of camp , at concentration up to 500 microm resulted in 1.5- to 1.7-fold increase in the peak cytosolic ca2+ concentration when cells were stimulated with 3 to 200 microm atp either in the presence or absence of extracellular ca2+ .
C1383501
cytosolic
C0007634
cells