| Autor: |
Skaddan, Marc B., Kilbourn, Michael R., Snyder, Scott E., Sherman, Phil S. |
| Zdroj: |
Journal of Cerebral Blood Flow and Metabolism; February 2001, Vol. 21 Issue: 2 p144-148, 5p |
| Abstrakt: |
Although the inhibition of acetylcholinesterase remains the primary treatment of Alzheimer's disease, little is known of the results of increased acetylcholine levels on muscarinic receptor occupancy or function. Using N-(2-[18F]fluoroethyl)-4-piperidyl benzilate ([18F]FEPB), a moderate affinity (Ki= 1.7 nmol/L) nonsubtype-selective muscarinic receptor antagonist, the authors examined the sensitivity of equilibrium in vivoradioligand binding in rat brain with changes in endogenous acetylcholine levels produced by treatments with acetylcholinesterase inhibitors. Phenserine administration 30 minutes before resulted in a dose-dependent increase in N-(2-[18F]fluoroethyl)-4-piperidyl benzilate binding to muscarinic cholinergic receptors, reaching a maximum increase of 90% in the striatum at a dose of 5 mg/kg intraperitoneally. Constant infusion of physostigmine at a dosage of 250 μg/kg/min produced an identical increase in radioligand binding. This agonist-induced increase of in vivomAChR radioligand binding offers a new method for monitoring of the efficacy of acetylcholinesterase inhibitors or other drugs to enhance acetylcholine actions at the muscarinic receptors. |
| Databáze: |
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