DEVELOPMENT OF A WHOLE-CELL HIGH-THROUGHPUT SCREEN FOR MUSCARINIC RECEPTOR AGONISTS

We have developed a high throughput screen using intact cells to ident ify muscarinic receptor agonists, Chinese hamster ovary cells stably t ransfected with the M1 muscarinic acetylcholine receptor (CHO-M1) were pre-labeled with [H-3]-arachidonic acid (AA), Stimulation of muscarin ic receptors with known muscarinic agonists resulted in release of AA from the cells into the culture medium, The released [H-3]-AA in this assay was counted using both standard scintillation methods and Luma P lates, Because muscarinic antagonists do not cause release of AA, only agonists are identified, A follow-up screen using a competitive antag onist was used to confirm agonist properties of active compounds, This screen was relatively simple, reproducible, and compatible with many organic solvents and natural products growth media, Thus, it may be us eful for the discovery of muscarinic agonists from natural product bro ths or synthetic compounds.