Figure 4.

The effect of an additional 20-acetate group to phorbol esters on the fractional stimulation-induced (S-I) outflow of radioactivity from rat cortex slices pre-incubated with [³H]-serotonin. There were four periods of electrical stimulation (each 1 Hz for 60 s) and drugs (dPAng; dPAngA; dPPhen; dPPhenA; PDA; PTA) were present during the second, third and fourth stimulation in increasing concentrations (0.1, 1.0 and 3.0 μM). All results are expressed as described in Figure 1 legend. Each symbol represents the mean and the vertical lines the standard error of the mean (s.e.mean). The number of experiments was between 4–10 for each drug. ^*Represents a significant difference from control, (P<0.05, Scheffé's test after two-way ANOVA). ⁺Represents a significant difference from the 20-acetate drugs (P<0.05, Scheffé's test after two-way ANOVA).