Concentration and time dependence of the effect of DEA/NO on adenosine kinase activity. Cultures were exposed to selected concentrations of DEA/NO before addition of radioactivity. Samples were taken at 5, 10, and 15 min after addition of radioactivity. The same data are plotted in A, with concentration as the independent variable, and in B with time as the independent variable. A, Clear concentration dependence is evident at the 10 and 15 min intervals. B, The accumulation of radioactivity appears to be linear over 15 min in the absence of DEA/NO. The experiment shown is representative of three experiments that were performed.