Endothelin receptor

Endothelin receptor is a type of G protein-coupled receptor that is activated by the protein endothelin. There are two types of endothelin receptors: ET_A and ET_B. These receptors play a crucial role in vasoconstriction, cell proliferation, and neurotransmission.

Structure

Endothelin receptors are integral membrane proteins that contain seven transmembrane domains, which is a common characteristic of G protein-coupled receptors. The ET_A and ET_B receptors share a 63% amino acid sequence identity.

Function

Endothelin receptors are found in various tissues, including the vascular smooth muscle, heart, lung, and kidney. They are involved in a variety of physiological processes.

ET_A Receptor

The ET_A receptor primarily mediates vasoconstriction and cell proliferation. It is predominantly found in vascular smooth muscle cells. Activation of the ET_A receptor by endothelin leads to vasoconstriction and cell proliferation.

ET_B Receptor

The ET_B receptor has a dual role. It is located in the endothelial cells where it mediates vasodilation by releasing nitric oxide and prostacyclin. It is also found in smooth muscle cells where it mediates vasoconstriction.

Clinical significance

Endothelin receptors have been implicated in a variety of diseases, including pulmonary arterial hypertension, heart failure, and cancer. Antagonists of the endothelin receptor, such as bosentan, ambrisentan, and macitentan, are used clinically to treat pulmonary arterial hypertension.

See also

• Endothelin
• G protein-coupled receptor
• Vasoconstriction
• Cell proliferation

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