α1-Adrenergic Receptors of MDCK-D1 Cells Utilize Multiple Signalling Components
We have examined mechanisms for signal transduction by α1-adrenergic receptors in a clonal cell line, Madin Darby canine kidney, MDCK-D1 These cells possess a pure population of α1B-adrenergic receptors (α1B-AR) that activate multiple phospholipases. We show here that these receptors have 2 other actions: release of cellular ATP and increase in cyclic AMP formation. The increase in cyclic AMP formation depends on formation of cyclo-oxygenase-dependent products, in particular, PGE2. We also show here that P2Y receptor agonists down-regulate α1-AR in a non-additive manner with AR agonist-promoted down-regulation. Taken together, the data indicate that α1B-AR in MDCK-D1 cells use multiple mechanisms for activation and deactivation of signalling. Cellular release of and response to ATP may modulate α1B-AR signalling.
KeywordsClonal Cell Line Cellular Release Stimulate cAMP Formation Multiple Signalling Component Multiple Phospholipase
Unable to display preview. Download preview PDF.
- 8.Meier KE, Sperling DM, and Insel PA, Agonist-mediated regulation of α1 and β2-adrenergic receptors in cloned MDCK cells, Am J Physiol 249, C69–77 (1985).Google Scholar
- 9.Schwiebert EM, ABC transporter-facilitated ATP conductive transport, Am J Physiol 276, C1–8 (1999).Google Scholar
- 12.Ruan Y, Kan H, Parmentier JH, Fatima S, Allen LF, and Malik KU, α1A-adrenergic receptor stimulation with phenylephrine promotes arachidonic acid release by activation of phospholipase D in rat-1 fibroblasts: inhibition by protein kinase A, J Pharmacol Exp Ther 284, 576–585 (1998).PubMedGoogle Scholar