Author/Editor		Čarman-Kržan, Marija; Lipnik-Štangelj, Metoda
Title		Molecular properties of central and peripheral histamine H1 and H2 receptors
Type		članek
Source		Pflugers Arch
Vol. and No.		Letnik 439, št. 3 Suppl
Publication year		2000
Volume		str. R131-2
Language		eng
Abstract		We identified and characterised histamine H1 and H2 receptor subtypes on rat cortical astrocytes in primary culture with radioligand binding studies and compared their molecular properties with peripheral (bovine vascular smooth muscle and endothelial cells) histamine H1 and H2 receptors. Our results showed the existence of a homogenous population of high affinity binding sites for 3H-mepyramine (Bmax= 281 fmol/mg protein, KD= 3.5 +/- 0.7 nM) and 3H-tiotidine (Bmax= 59 fmol/mg protein, KD 1.9 +/- 0.7 nM) on astrocytes, which was further confirmed by competition binding studies using various H1 and H2 specific agonists/antagonists. We showed differences in the density of receptors and differences in the affinities of competing drugs for the same histamine receptor subtype (H1 and H2) between the tissues used, which indicate different molecular properties of the central and peripheral histamine receptors.
Descriptors		RECEPTORS, HISTAMINE H1 RECEPTORS, HISTAMINE H2 ASTROCYTES ENDOTHELIUM, VASCULAR MUSCLE, SMOOTH, VASCULAR RATS CATTLE RADIOLIGAND ASSAY