Evaluation of in vivo selective binding of [11C]doxepin to histamine H1 receptors in five animal species.
The specific binding of [(11)C]doxepin, which has been used as a radioligand for mapping histamine H(1) receptors in human brain by positron emission tomography, was evaluated in five animal species. In mice the [(11)C]doxepin uptake was reduced by treatment with cold doxepin and two H(1) receptor antagonists, but not with H(2)/H(3) antagonists. The specific binding evaluated with treatment with (+)-chlorpheniramine (H(1) antagonist) was in the range of 10-30% in mouse, rat, rabbit, and monkey, but was not detected in guinea pig.
Ishiwata
Kiichi
K
Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, 1-1 Naka-cho, Itabashi-ku, Tokyo 173-0022, Japan. ishiwata@pet.tmig.or.jp
Kawamura
Kazunori
K
Wang
Wei-Fang
WF
Tsukada
Hideo
H
Harada
Norihiro
N
Mochizuki
Hideki
H
Kimura
Yuichi
Y
Ishii
Kenji
K
Iwata
Ren
R
Yanai
Kazuhiko
K
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism*; D002250:Carbon Radioisotopes / Q000493:pharmacokinetics; D004316:Doxepin / Q000493:pharmacokinetics*; D006168:Guinea Pigs; D017442:Histamine Agonists / Q000494:pharmacology; D006801:Humans; D008253:Macaca mulatta; D008297:Male; D008657:Metabolic Clearance Rate; D051379:Mice; D011485:Protein Binding; D011817:Rabbits; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D011969:Receptors, Histamine H1 / Q000378:metabolism*; D013045:Species Specificity; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed / Q000379:methods
D002250:Carbon Radioisotopes; D017442:Histamine Agonists; D019275:Radiopharmaceuticals; D011969:Receptors, Histamine H1; D004316:Doxepin