Characterization of histamine H1-receptors on astrocytes in primary culture: [3H]mepyramine binding studies.
The characteristics of histamine H1-receptors on astrocytes from the cerebral cortex of newborn rats in primary culture were analyzed with a [3H]mepyramine binding assay, and compared with those in the cerebral cortex. The apparent dissociation constant (KD) of [3H]mepyramine binding, the apparent inhibition constants (Ki) of various H1-ligands for [3H]mepyramine binding and the stereoselectivity of d- and l-chlorpheniramine for the inhibition of [3H]mepyramine binding to receptors on cultured astrocytes and to receptors in the brain tissue were very similar, indicating that these receptors are identical. The apparent density of H1-receptors (Bmax) on astrocytes was 262 +/- 60 fmol/mg protein, which was comparable to that in the brain tissue (194 +/- 24 fmol/mg protein). The development of H1-receptors on cultured astrocytes resembled the postnatal development of the receptors in the rat brain. These results suggest that astrocytes could be one of the main targets of the central histaminergic system.
Inagaki
N
N
Department of Pharmacology II, Faculty of Medicine, Osaka University, Japan.
Fukui
H
H
Taguchi
Y
Y
Wang
N P
NP
Yamatodani
A
A
Wada
H
H
D000631:Aminopyridines / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D001253:Astrocytes / Q000378:metabolism*; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D002478:Cells, Cultured; D006634:Histamine H1 Antagonists / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D011738:Pyrilamine / Q000378:metabolism*; D051381:Rats; D011969:Receptors, Histamine H1 / Q000378:metabolism*
D000631:Aminopyridines; D006634:Histamine H1 Antagonists; D011969:Receptors, Histamine H1; D011738:Pyrilamine