Biochemical characterization of histamine H1 receptors in bovine adrenal medulla.
Bovine adrenal medullary membranes display high affinity and saturable binding to [3H]mepyramine, a selective H1 antagonist, with Kd of 1.5 +/- 0.1 nM and Bmax of 694 +/- 12 fmol/mg protein. [3H]Azidobenzpyramine, an azidobenzamide derivative of mepyramine, was synthesized and used to photolabel the high affinity mepyramine binding sites. Following photolysis, a protein component with an approximate molecular weight of 53-58 kDa was shown to be covalently labeled, as judged by gel filtration and SDS/PAGE; labeling being greatly reduced in the presence of excess unlabeled mepyramine. These results indicate that bovine adrenal medulla expresses a large number of H1 receptors, which are pharmacologically and biochemically indistinguishable from the H1 receptor of many other tissues of various species.
Yamashita
M
M
Department of Pharmacology II, Osaka University Faculty of Medicine, Suita, Japan.
Ito
S
S
Sugama
K
K
Fukui
H
H
Smith
B
B
Nakanishi
K
K
Wada
H
H
D000313:Adrenal Medulla / Q000378:metabolism*; D000345:Affinity Labels / Q000378:metabolism; D000818:Animals; D001386:Azides / Q000378:metabolism*; D001667:Binding, Competitive; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008970:Molecular Weight; D010782:Photolysis; D011738:Pyrilamine / Q000031:analogs & derivatives* / Q000378:metabolism*; D011969:Receptors, Histamine H1 / Q000302:isolation & purification / Q000378:metabolism*
D000345:Affinity Labels; D001386:Azides; D011969:Receptors, Histamine H1; C069486:4-azidobenzpyramine; D011738:Pyrilamine