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Titolo:
Effects of calyculin A and okadaic acid on acetylcholine release and subcellular distribution in rat hippocampal formation
Autore:
Issa, AM; Gauthier, S; Collier, B;
Indirizzi:
McGill Univ, Dept Pharmacol & Therapeut, Montreal, PQ H3G 1Y6, Canada McGill Univ Montreal PQ Canada H3G 1Y6 peut, Montreal, PQ H3G 1Y6, Canada McGill Univ, Dept Neurosurg, Montreal, PQ H3G 1Y6, Canada McGill Univ Montreal PQ Canada H3G 1Y6 surg, Montreal, PQ H3G 1Y6, Canada McGill Univ, Ctr Studies Aging, Montreal, PQ H3G 1Y6, Canada McGill Univ Montreal PQ Canada H3G 1Y6 ging, Montreal, PQ H3G 1Y6, Canada
Titolo Testata:
JOURNAL OF NEUROCHEMISTRY
fascicolo: 1, volume: 72, anno: 1999,
pagine: 166 - 173
SICI:
0022-3042(199901)72:1<166:EOCAAO>2.0.ZU;2-4
Fonte:
ISI
Lingua:
ENG
Soggetto:
CHOLINERGIC SYNAPTIC VESICLES; NERVE-TERMINALS; TRANSMITTER RELEASE; NEUROMUSCULAR-JUNCTION; PROTEIN PHOSPHATASES; GENE LOCUS; TRANSPORTER; EXOCYTOSIS; STORAGE; HETEROGENEITY;
Keywords:
okadaic acid; calyculin A; acetylcholine compartmentation; acetylcholine release; synaptic vesicle heterogeneity;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
50
Recensione:
Indirizzi per estratti:
Indirizzo: Issa, AM McGill Univ, Dept Pharmacol & Therapeut, 3655 Drummond St, Montreal, PQ H3G McGill Univ 3655 Drummond St Montreal PQ Canada H3G 1Y6 l, PQ H3G
Citazione:
A.M. Issa et al., "Effects of calyculin A and okadaic acid on acetylcholine release and subcellular distribution in rat hippocampal formation", J NEUROCHEM, 72(1), 1999, pp. 166-173

Abstract

The mechanisms regulating the compartmentation of acetylcholine (ACh) and the relationship between transmitter release and ACh stores are not fully understood. In the present experiments, we investigated whether the inhibitors of serine/threonine phosphatases 1 and 2A, calyculin A and okadaic acid,alter subcellular distribution and the release of ACh in rat hippocampal slices. Calyculin A and okadaic acid significantly (p < 0.05) depleted the occluded ACh of the vesicular P-3 fraction, but cytoplasmic ACh contained inthe S-3 fraction was not significantly affected. The P-3 fraction is knownto be heterogeneous; calyculin A and okadaic acid reduced significantly (p< 0.05) the amount of ACh recovered with a monodispersed fraction (D) of synaptic vesicles, but the other nerve terminal bound pools (E-F and G-H) were not so affected. K+-evoked ACh release decreased significantly (p < 0.01) in the presence of calyculin A and okadaic acid, suggesting that fractionD's vesicular store of ACh contributes to transmitter release. The loss ofACh from synaptic vesicle fractions prepared from tissue exposed to phosphatase inhibitors appeared not to result from a reduced ability to take up ACh. Thus, when tissue was allowed to synthesize [H-3]ACh from [H-3]choline,the ratio of [H-3]ACh in the S-3 to P-3 fractions was not much changed by exposure of tissue to calyculin A or okadaic acid; furthermore, the specific activity of ACh recovered from the D fraction was not reduced disproportionately to that of cytosolic ACh. The changes are considered to reflect reduced synthesis of ACh by tissue treated with the phosphatase inhibitors, rather than an effect on vesicle uptake mechanisms. Thus, exposure of tissue to calyculin A or okadaic acid appears to produce selective depletion of tissue ACh content in a subpopulation of synaptic vesicles, suggesting that phosphatases play a role in ACh compartmentation.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/03/20 alle ore 09:11:50