title: Pharmacological studies of geissoschizine methyl ether, isolated from Uncaria sinensis Oliv., in the central nervous system.
abstract: The pharmacological properties of geissoschizine methyl ether, isolated from Uncaria sinensis Oliv., were analyzed in vitro and in vivo using mice central serotonin neurons. In the in vitro experiment, geissoschizine methyl ether inhibited [3H]8-hydroxy-2-(di-n-propylamino)tetralin) ([3H]8-OH-DPAT) (K(i)=0.8 microM), [3H]mesulergine (K(i)=0.9 microM) and [3H]ketanserin (K(i)=1.4 microM), but had less affinity toward [3H]prazosin (K(i) > 10 microM) and [3H]spiperone (K(i) >15 microM) binding to mouse brain membranes. The in vivo studies showed that geissoschizine methyl ether dose-dependently reduced 5-hydroxy-L-tryptophan (I-5-HTP) plus clorgyline-induced head twitch response without inhibiting the I-5-HTP plus clorgyline and 8-OH-DPAT-induced head weaving. On the other hand, geissoschizine methyl ether also decreased the rectal temperature of mice (hypothermic response) in a dose-dependent manner. These results suggest that geissoschizine methyl ether possesses mixed 5-HT(1A) receptor agonist/5-HT(2A/2C) receptor antagonist activities and inhibits the head twitch response by blocking the 5-HT(2A) receptors, and possibly, at least in part, by stimulating the 5-HT(1A) receptors in the central nervous system.
authors.affiliation: Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Aramaki, Sendai 980-8578, Aoba, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Pengsuparp
authors.forename: B
authors.initials: B
authors.lastname: Indra
authors.forename: O
authors.initials: O
authors.lastname: Nakagawasai
authors.forename: T
authors.initials: T
authors.lastname: Tadano
authors.forename: Y
authors.initials: Y
authors.lastname: Mimaki
authors.forename: Y
authors.initials: Y
authors.lastname: Sashida
authors.forename: Y
authors.initials: Y
authors.lastname: Ohizumi
authors.forename: K
authors.initials: K
authors.lastname: Kisara
mesh_terms: D006916:5-Hydroxytryptophan / Q000494:pharmacology; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001667:Binding, Competitive / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002490:Central Nervous System / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D026121:Indole Alkaloids; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D011869:Radioligand Assay; D012007:Rectum / Q000502:physiology; D014316:Tritium
chemical_list: D004365:Drugs, Chinese Herbal; D026121:Indole Alkaloids; D007211:Indoles; C110832:geissoschizine methylether; D014316:Tritium; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D006916:5-Hydroxytryptophan