M. Hara et al., ENDOTHELIN ETB RECEPTORS SHOW DIFFERENT BINDING PROFILES IN INTACT-CELLS AND CELL-MEMBRANE PREPARATIONS, European journal of pharmacology, 345(3), 1998, pp. 339-342
We examined the affinity of endothelin-l, endothelin-3 and four endoth
elin receptor ligands, BQ788 dimethylpiperidinocarbonyl-gamma-methyl-l
eu-D-Trp( 1-CO2CH3-D-Nle-ONa), SE-209670 hoxyphenyl)-1-(3,4-methylened
ioxyphenyl)-5-(prop-1 -yloxy)indane-2-carboxylic acid), IRL-1620 (succ
inyl-[Glu(9),Ala(11,15)]endothelin-1(8-21)), and L-749329 oxyphenoxy)-
N-(4-isopropyl-phenylsulfonyl)-benzene acetamide), for endothelin ETB
receptors in human and rat heart cells. The affinities of these ligand
s showed good correlation between both types of living cells and betwe
en their membrane preparations (r = 0.861, P < 0.001), but less signif
icant correlation between each of the living cells and its respective
membrane preparation (r = 0.569, 0.02 < P < 0.05). These results sugge
st that there is no species difference in the affinities of these liga
nds and that destruction of the intact cell membrane structure may lea
d to changes in binding properties of the endothelin ETB receptor. (C)
1998 Elsevier Science B.V.