Fig. 3. Effects of IBMX on tentacle ectodermal cAMP content following treatment with and without N-acetylneuraminic acid (NANA). A group of sea anemones starved for 72h was incubated in filtered, natural sea water, pH7.65, with or without 10^-4moll^-1 IBMX for 20min (open columns). A second group of sea anemones starved for 72h was incubated in filtered, natural sea water, pH7.65, containing 1.8x10^-5moll^-1 NANA with or without 10^-4moll^-1 IBMX for 20min (filled columns). Individual tentacles from each group were snap-frozen, extracted and assayed for ectodermal cAMP using 1moll^-1 formic acid. Data are expressed as fmolcAMPµg^-1protein. Four anemones were used. Values are means ± S.E.M. (n=8 samples).