ISSN:
1432-1912
Keywords:
Receptors
;
3H-5-HT
;
3H-spiroperidol
;
3H-methiothepin binding
;
5-HT-sensitive adenylate cyclase
;
Supersensitivity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary A single treatment with a large dose of methiothepin (20 mg/kg, i.p.) induced, as early as the 2nd day after injection, a significant increase (+20–35%) in the number of specific binding sites for 3H-5-HT in forebrain areas, particularly the hippocampus. Experiments with 3H-methiothepin indicated that the drug remained firmly bound to brain membranes thus maintaining a local concentration high enough to effectively block 5-HT receptors for 10–12 h after its peripheral administration. Accordingly, it can be concluded that the occupancy of central 5-HT receptor sites by methiothepin for several hours was sufficient to induce a supersensitivity phenomenon within the two following days. Although 3H-methiothepin was a useful marker for analyzing the disposition and the kinetics of the 5-HT antagonist in brain tissues, it could not be used as a specific ligand of 5-HT receptors in brain since under in vitro as well as in vivo conditions most of 3H-methiothepin bound to non-specific sites, especially to the lipid component of the membranes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00499871
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