VIP/PACAP receptor activation stimulates the production of [cAMP]i and [Ca2+]i by coupling to independent G-protein subunits, although agonist potencies for the different transduction pathways appear to differ. Using CHO-K1 cells stably expressing the human VIP/PACAP receptors (hVPAC1R, hVPAC2R, and hPAC1R), functional assays ([cAMP]i and [Ca2+]i) were established and the receptor pharmacology was characterized with five peptide agonists (VIP, PACAP-27, PACAP-38, [Ala(11,22,28)]VIP, and R3P65). The rank order of potency (ROP) was consistent between assays for the individual receptor subtypes, however, higher agonist concentrations (approximately 100-fold) were required for stimulating [Ca2+]i when compared to [cAMP]i.
No takes yet. Share an insight, caveat, or question.
Dickson et al. (2006) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: