Figure 2. Effects of PKA inhibition on the release of [³H]CA elicited by moderate hypoxia.

A and B represent mean time courses of the release obtained in 6 control CBs challenged twice with a hypoxic stimulus (7% O₂-equilibrated solutions), and in 6 experimental CBs similarly stimulated except that 30 min prior to and during the second hypoxic challenge, 1 μm H-89 was present in the incubating solution. C, results of similar experiments using the three indicated PKA inhibitors; bars represent ratios of total evoked release obtained in the second challenge to that obtained in the first one (S2/S1) for control (open bars) and experimental CBs (grey bars). Values are means ±s.e.m. for 6–8 CBs.