Document Type |
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Article In Journal |
Document Title |
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Studies on the diversity of muscarinic receptors in the autoregulation of acetylcholine release in the rodent cerebrum using furan analogs of muscarine Studies on the diversity of muscarinic receptors in the autoregulation of acetylcholine release in the rodent cerebrum using furan analogs of muscarine |
Subject |
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Pharmacology |
Document Language |
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English |
Abstract |
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Previous studies have indicated that two fccdback mechanisms, onc positive and the
other negative, regulate the ratc of acctylcholinc (ACh) rclcasc.’-3 Thc positive
feedback system has at least three components: a muscarinic receptor (Ms), release
of substance P (SP), and influx of extracellular Ca2+. If the amount of ACh released
from the presynaptic nerve terminal is low, the released ACh activates Ms, which
stimulates the release of SP. Substance P increases Ca2+ influx, resulting in the
release of further quantities of ACh for effective cholinergic transmission. Similarly,
thrcc componcnts are present in thc ncgative feedback systcm: a presynaptic
muscarinic receptor (Mi), release of methionine enkephalin (MEK), and inhibition
of Ca2+ influx. If the ACh in the synaptic gap is high, it activates Mi, resulting in the
release of MEK. Methionine enkephalin decreases CaZ+ influx which decreases the
rate of release of ACh from the cholinergic nerve terminal. The critical first step in
both of these feedback systems is activation of presynaptic muscarinic receptors, Ms
and Mi. No selective agonists have been described for presynaptic muscarinic
receptors. Therefore, we studied the effects of 5-methylfurfuryltrimethylammonium
(5-MFT) and 5-hydrnxyfurfurltrimethylammonium (5-HMFT) on the simultaneous
release of ACh, SP, and MEK from the superfused mouse cerebral slices in our
search for selective agonists for Ms and Mi receptors. 5-MFT and 5-HMFT were
sclcctcd for this purpose bccausc thcy have diverse effects in the peripheral nervous system |
ISSN |
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0077-8923 |
Journal Name |
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Annals of the New York Academy of Sciences |
Volume |
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10 |
Issue Number |
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1 |
Publishing Year |
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1415 AH
1995 AD |
Article Type |
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Article |
Added Date |
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Wednesday, March 30, 2011 |
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Researchers
أسامة طيب | Tayeb, osama | Researcher | Doctorate | |
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