Overview
- Okada, M. and Nishikibe, M. (2002) Cardiovasc. Drug Rev. 20, 53.
Alomone Labs BQ788 inhibits ET-B receptor-mediated Ca2+ mobilization in CHO cells.Dose-response plot of BQ788 (#B-175) inhibition of ET-B receptor-mediated, endothelin-1-evoked Ca2+ mobilization (IC50 = 6.57 nM). Cells were loaded with Calcium 6 dye, incubated with BQ788, and stimulated with 30 nM endothelin-1 (EC80). Changes in intracellular Ca2+ levels were detected as changes in maximum relative fluorescence (RLU) using FLIPRTETRA™.
BQ788 is a synthetic modified tripeptide that acts as a potent, selective and competitive antagonist of the ET-B (endothelin B) receptor, a receptor that belongs to the G-protein coupled receptor (GPCR) superfamily. BQ788 is a soluble compound that does not bind plasma proteins and is metabolized in a short period of time. It lacks oral bioavailability and requires intra-arterial administration. The compound is used in vitro and in vivo to demonstrate the role of endogenous and exogenous endothelin receptor subtypes in physiological and pathophysiological conditions1,2. It displays IC50 values of 1.2 nM in radiolabeled Girardi heart cells and 1300 nM in human neuroblastoma cell line, respectively1.
ET-A and ET-B receptors are widely distributed in vascular tissues where they mediate vasoconstriction and in nonvascular tissues such as the liver, kidney, and brain. ET-A receptors have high affinity for ET-1 and ET-2 peptides and relatively low affinity for ET-3, while ET-B receptors show high affinity for all ET isopeptides1.
