Figure 5. Effect of 5 mm nucleotide in the presence of 5 mm ATP.

Each point is the mean ± s.e.m. expressed as a percentage of the control response obtained in the presence of 5 mm ATP alone, using the protocol shown in Fig. 2A. Mean Ca²⁺ transient amplitude in the presence of 5 mm ATP or 5 mm ATP in combination with 5 mm ADP, AMP, adenosine or CTP. * Responses significantly different (P < 0.05) from those obtained in the presence of 5 mm ATP. The number of preparations is indicated in parentheses.