Fig. 4.

The PACAP-induced rise in intracellular Ca²⁺ was not eliminated by inhibition of Src family kinases. A: traces illustrating the transient rise in intracellular Ca²⁺ during PACAP treatment of PAC1 receptor cells at room temperature (~24°C). B: pretreatment at 37°C for 15 min with the Src family inhibitor PP1 (10 µM) had no effect on the PACAP-induced rise in intracellular calcium measured at 24°C. C: PACAP also elicited a marked rise in intracellular calcium recorded at 34°C following a 15-min pretreatment at 37°C with 10 µM PP2. Each trace in all panels is from an individual cell; the arrows indicate approximate initiation of 25 nM PACAP addition to the recording bath. Following the rapid rise in intracellular Ca²⁺ in PACAP, the signal decayed slowly toward a steady lower plateau (not shown).