Fig. 4.

cAMP signaling requires extracellular Ca⁺² to activate ovary ECD production but is not elevated by OEH or ILP3. (A) The cAMP analog 8-pCPT-cAMP stimulated ECD production by ovaries only in the presence of extracellular Ca⁺². Ovaries were placed into saline containing 0, 1.7, or 8.5 mM Ca⁺² without or with 8-pCPT-cAMP (100 uM) followed by determination of ECD in the medium and statistical analysis as described in Fig. 1 (F_{6, 54}= 17.6, P < 0.0001). (B) OEH and ILP3 treatment did not elevate intracellular cAMP in ovaries above the medium only negative control, whereas NKH 477 increased intracellular cAMP levels 5 fold. Triplicate sets of ovaries were incubated for 30 min in Sf-900 II SFM medium only (control) or medium containing OEH (330 nM), ILP3 (400 nM), or NKH 477 (8.3 mM) plus IBMX (0.83 mM). cAMP per ovary pair was then determined by EIA and analyzed as described in Fig. 1 (F_{3, 11} = 6.796, P = 0.0074 and Tukey’s multiple comparison test, α = 0.05).