Avtor/Urednik		Kržan, M; Erjavec, F; Čarman-Kržan, M
Naslov		Characterization of coexistent histamine H1- and H2-receptor binding sites in the purified guinea pig myocardial membranes from ventricles
Tip		članek
Vir		Agents Actions
Vol. in št.		Letnik 38
Leto izdaje		1993
Obseg		str. C289-91
Jezik		eng
Abstrakt		In the present work, we identified and characterised histamine H1- and H2-receptors in highly purified myocardial membranes isolated from female guinea pig ventricles. We determined the binding parameters for the interactions of 3H-mepycamine with the histamine H1-receptor binding site and 3H-tiotidine with the histamine H2-receptor binding site. Binding of both ligands in our study was saturable, reversible and of high affinity. Scatchard's analysis ofthe specific 3H-mepyramine binding reve3led the existence of high and low affinity binding sites with apparent KD values of 0.4 nM and 4.5 nM, respectively. The density of binding sites (Bmax) was 100 fmol/mg protein for the high and 466 fmol/mg protein for the low affinity binding site. 3H-tiotidine binds to a single population of binding sites with a KD, of 1.0 nM and a Bmax of 27 fmol/mg protein. These data suggest that both histamine H1- and H2-receptors eoexist in the guinea pig myocardium with a significantly higher prevalence of the histamine H1-receptor population.
Deskriptorji		HEART VENTRICLE MEMBRANES RECEPTORS, HISTAMINE H1 RECEPTORS, HISTAMINE H2 GUINEA PIGS PYRILAMINE MYOCARDIUM TRITIUM RADIOLIGAND ASSAY