Continuous monitoring of ATP levels in living insulin secreting cells expressing cytosolic firefly luciferase

The second messenger role of ATP in insulin secretion was investigated in living INS-I insulinoma cells, ATP-dependent luminescence was monitored in cells expressing high levels of firefly luciferase under the control of the tetracycline-dependent transactivator, The calibration of luminescence in permeabilized cells yielded similar ATP levels as those obtained in cell extracts with a conventional ATP assay, Stimulation of insulin secretion by glucose or methyl-succinate was correlated with rises of cellular ATP in simultaneous measurements. ATP generation was decreased by inhibition of the ADP-ATP translocase, This approach demonstrates the feasibility of defining the dynamic relationship between ATP and other parameters involved in metabolism-secretion coupling. (C) 1998 Federation of European Biochemical Societies.