Endothelin receptors and antagonists

Endothelin receptors and antagonists

Endothelin receptors have been subdivided into ET_A and ET_B. ET_B has been further subdivided into ET_B1 and ET_B2. All these are G protein coupled receptors.

Sitaxentan, ambrisentan and atrasentan are selective endothelin A (ET_A) receptor antagonists. Bosentan, Macitentan and Tezosentan are non selective inhibitors which act on both ET_A and ET_B receptors. Endothelin receptor antagonists have been used in the treatment of pulmonary hypertension. ET_B blockade is not beneficial in pulmonary hypertension as it will interfere with nitric oxide activity and hence ambrisentan has an edge over bosentan in this respect.

The endothelin (ET) axis which includes ET-1, ET-2 and ET-3 has been shown to have a role in tumor growth as well.