Chronic imipramine treatment-induced changes in acetylcholinesterase (EC activity in discrete rat brain regions

Chronic imipramine treatment-induced changes in acetylcholinesterase (EC activity in discrete rat brain regions

Author Camarini, Rosana Autor UNIFESP Google Scholar
Venditti, Marco Antonio Campana Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract Cholinergic as well as monoaminergic neurotransmission seems to be involved in the etiology of affective disorders. Chronic treatment with imipramine, a classical antidepressant drug, induces adaptive changes in monoaminergic neurotransmission. In order to identify possible changes in cholinergic neurotransmission we measured total, membrane-bound and soluble acetylcholinesterase (Achase) activity in several rat brain regions after chronic imipramine treatment. Changes in Achase activity would indicate alterations in acetylcholine (Ach) availability to bind to its receptors in the synaptic cleft. Male rats were treated with imipramine (20 mg/kg, ip) for 21 days, once a day. Twenty-four hours after the last dose the rats were sacrificed and homogenates from several brain regions were prepared. Membrane-bound Achase activity (nmol thiocholine formed min-1 mg protein-1) after chronic imipramine treatment was significantly decreased in the hippocampus (control = 188.8 ± 19.4, imipramine = 154.4 ± 7.5, P<0.005) and striatum (control = 850.9 ± 59.6, imipramine = 742.5 ± 34.7, P<0.005). A small increase in total Achase activity was observed in the medulla oblongata and pons. No changes in enzyme activity were detected in the thalamus or total cerebral cortex. Since the levels of Achase seem to be enhanced through the interaction between Ach and its receptors, a decrease in Achase activity may indicate decreased Ach release by the nerve endings. Therefore, our data indicate that cholinergic neurotransmission is decreased after chronic imipramine treatment which is consistent with the idea of an interaction between monoaminergic and cholinergic neurotransmission in the antidepressant effect of imipramine
Keywords acetylcholinesterase
Language English
Date 1997-08-01
Published in Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 30, n. 8, p. 955-960, 1997.
ISSN 0100-879X (Sherpa/Romeo, impact factor)
Publisher Associação Brasileira de Divulgação Científica
Extent 955-960
Access rights Open access Open Access
Type Article
Web of Science ID WOS:A1997XT03600007
SciELO ID S0100-879X1997000800007 (statistics in SciELO)

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