- Alomone Labs FR 139317 inhibits ET-A receptor-mediated Ca2+ mobilization in CHO-K1 cells.Dose-response curve of FR 139317 (#F-180) inhibition of ET-A receptor-mediated, Endothelin-1-evoked Ca2+ mobilization. IC50 was determined at 25.97 nM. Cells were loaded with Calcium 6 dye, incubated with FR 139317, and stimulated with 15 nM Endothelin-1 (EC80). Changes in intracellular Ca2+ levels were detected as changes in maximum relative fluorescence (RLU) using FLIPRTETRA™.
FR 139317 is a synthetic linear tripeptide that acts as a potent, competitive and highly selective antagonist of endothelin A (ET-A) receptors. FR 139317 can be used as a useful tool to investigate the physiological properties of ET-A receptor and to explore its role in diseases1,2. FR139317 inhibits the specific binding of radio labeled endothelin 1 to porcine aortic microsomes in a concentration-dependent, monophasic manner with an IC50 value of 0.53 nM2.
Endothelin receptors include two subtypes: ET-A and ET-B. They are widely distributed in vascular and nonvascular tissues. The ET-A receptor has a high specificity towards endothelin-1 and endothelin-2. It is expressed in vascular smooth muscle cells and mediates vasoconstriction3.
FR 139317 (#F-180) is a highly pure, synthetic, and biologically active compound.