cAMP response of bf98C and bf95 to graded concentrations of peptides. Effects of (A) bfPTH-like, (B) vertebrate PTH and PTHrP, and (C) vertebrate PACAP or VIP on graded peptide concentrations assessed as intracellular cAMP accumulation in bf98C-expressing cells. (D) Measurement of intracellular cAMP elevation in CHO-K1 cells transiently expressing bf95 in response to graded concentrations of endogenous ligands, bfPACAP/GLUC peptides (bfPACAP/GLUCa, bfPACAP/GLUCb, and bfPACAP/GLUCc). Data are means ± SEM from at least three experiments performed in triplicate.