Overview
- Moreland, S. (1994) Cardiovasc. Ther. 12, 48.
Alomone Labs BQ-123 sodium salt inhibits ET-A receptor-mediated Ca2+ mobilization in CHO cells.Dose-response curve of BQ-123 sodium salt (#B-185) inhibition of the ET-A receptor-mediated, endothelin-1-evoked Ca2+ mobilization. Cells were loaded with Calcium 6 dye, incubated with BQ-123 sodium salt, and stimulated with 15 nM endothelin-1 (EC80). Changes in intracellular Ca2+ levels were detected as changes in maximum relative fluorescence (RLU) using FLIPRTETRA™.
BQ-123 is a cyclic pentapeptide that acts as potent and selective antagonist of endothelin A (ET-A) receptors. BQ-123 exhibits a 1000-fold selectivity for ET-A receptors over ET-B receptors. It antagonizes endothelin-1 radioligand binding to ET-A and ET-B receptors with IC50 values of 22 nM and 18 µM, respectively1.
Studies show that BQ-123 prevents production of TNF-α and IL-6 in skeletal muscle of LPS-treated rat and enhances antioxidant defense1,2.
There are two subtypes of endothelin receptor: ET-A and ET-B. They are widely distributed in vascular and nonvascular tissues. ET-A receptors are predominantly expressed in peripheral tissues, especially in vascular smooth muscle where they mediate vasoconstriction. They are also detected in several regions of the brain. The ET-A receptor has high affinity for endothelin-1 and endothelin-2 and relatively low affinity for endothelin-3, while the ET-B receptor has high affinity for all endothelin isopeptides3.
