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Abstract:
The regulation of muscarinic acetylcholine receptors by short-term exposure to agonists was investigated in intact mouse neuroblastoma (clone N1E- 115) cells, using the hydrophilic ligand (tritium)N-methylscopolamine. It was found that preincubation of cells with 1 mM carbamylcholine for 30 min at 37 C, followed by extensive washing, led to a significant reduction in the subsequent specific binding of 0.2 nM (tritium)N-methylscopolamine. Regulation of muscarinic acetylcholine receptor sensitivity and density was examined upon pre- exposure to muscarinic receptor agonists. Pretreatment of neuronal cells in culture resulted in a significant decrease in the response in phosphoinositude hydrolysis. This treatment also resulted in a decrease in the concentration of cell surface muscarinic receptors. This decrease in receptors ligands. However, it resulted in a selective decrease in the relative densities of M sub 1 muscarinic receptors which have a high affinity for the selective antagonist pirenzepine. Activation of protein kinase C by phorbol esters also resulted in decreasing the responsiveness of muscarinic receptors. However, there was no change in receptor density. Keywords: Muscarinic antagonists, Atropine, Scopolamine, Quinuclidinyl benzilate(QNB). (aw)
| Limitations: |
 APPROVED FOR PUBLIC RELEASE |
| Description: |
Final rept. Apr 85-Apr 88 |
| Pages: |
11 |
| Report Date: |
22 JUN 88 |
| Contract Number: |
DAAG29-85-K-0123 |
| Report Number: |
A075791 |
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Keywords relating to this report:
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