[3H]N‐Methylscopolamine Binding Studies Reveal M2 and M3 Muscarinic Receptor Subtypes on Cerebellar Granule Cells in Primary Culture

• DOI: 10.1111/j.1471-4159.1990.tb08856.x
• Publication Date: 2006-10-06T00:17:43Z
• Authors: R. Alonso; M. Didier; P. Soubrie
• Keywords: Methoctramine; Muscarinic antagonist

Abstract: Saturation experiments with the muscarinic antagonist [ 3 H] N ‐methylscopolamine ([ H]NMS) indicated that cerebellar granule cells in primary culture possess a high density of acetylcholine receptors (mAChRs): B max = 1.85 ± 0.01 pmol/mg protein at 10 days culture; K D 0.128 n M The selective 1 pirenzepine displaced H]NMS binding low affinity ( i 273 13 ), whereas 2 /M 4‐diphenylacetoxy‐ ‐methylpiperidine methiodide competed values nanomolar range, result suggesting some mAChRs on belong to subtype. Methoctramine, which discriminates between and subtypes affinity, respectively, displayed for sites i(H) 31 5 ; i(L) 2,620 320 ). These results provide first demonstration both mAChR may be present cultured cells. In addition, complete death neurons induced by ‐methyl‐D‐aspartate (100 μM h) reduced 85% specific H]NMS, indicating most were associated neuronal components. Finally, evolution mAChRs, labeled correlated maturation during vitro development these