A68930 is a potent, full agonist at dopamine1 (D1) receptors in renal epithelial LLC‐PK1 cells

The selective dopamine1 (D1) receptor agonists SK&F 82526 (fenoldopam) and A68930 and the mixed D1/D2 agonist SK&F 85174 were tested for their ability to stimulate adenosine 3′:5′‐cyclic monophosphate (cyclic AMP) accumulation in the porcine renal epithelial cell line, LLC‐PK1. SK&F 82526 and SK&F 85174 were potent stimulators of cyclic AMP accumulation (EC50s 21.4 and 14.5 nm, respectively), but only partial agonists (intrinsic activities 31% and 46% of dopamine respectively). In contrast, A68930 was a potent, full agonist (EC50 12.7 nm, intrinsic activity 102% of dopamine). The stimulatory effects of A68930 and dopamine on cyclic AMP accumulation were not additive, and the stimulation of cyclic AMP accumulation by A68930 was blocked by the D1‐selective antagonist, SCH 23390. These properties of A68930 suggest that it may be a useful D1‐selective agonist to study renal D1 receptor mechanisms in vitro and in vivo.