ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
: Dopamine or agonists with D1 receptor potency stimulated cyclic AMP (cAMP) accumulation in whole cell preparations of NS20Y neuroblastoma cells. The accumulation of cAMP after D1 stimulation was rapid and linear for 3 min. Both dopamine and the novel D1 receptor agonist dihydrexidine stimulated cAMP accumulation two-to threefold over baseline. The pseudo-Km for dopamine was ⋍2 μM, whereas for dihydrexidine it was ⋍30 nM. The effects of both drugs were blocked by either the D1-selective antagonist SCH23390 (Ki, 0.3 nM) or the nonselective antagonist (+)-butaclamol (Ki, 5 nM). Both (−)-butaclamol and the D2-selective antagonist (−)-sulpiride were ineffective (Ki 〉 3 μM). Forskolin (10 μM), prostaglandin E1 (1 μM), and adenosine (10 μM) also stimulated cAMP accumulation, but none were antagonized by SCH23390 (1 μM). Finally, muscarinic receptor stimulation (100 μM carbachol) inhibited both D1-and forskolin-stimulated increases in cAMP accumulation by 80%. The present results indicate that NS20Y neuroblastoma cells have D1 receptors that are coupled to adenylate cyclase, and that these receptors have a pharmacological profile similar to that of the D1 receptor(s) found in rat striatum.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1991.tb06352.x
