[Structure and function of the prostanoid receptors in cardiovascular system].

Recently, cDNAs for TXA2 and PGE2 (EP3 and EP2) receptors have been cloned and their primary structure elucidated. They belong to a G-protein coupled, rhodopsin-type receptor superfamily. The TXA2 receptor has been most extensively analyzed biochemically, pharmacologically and molecular biologically. Its genomic structure has also been elucidated. The EP3 receptor has several isotypes, which are generated by alternative splicing at its C-terminus. These isotypes show different efficiency in their coupling to G-proteins. EP2 receptor shares some features with adrenergic receptors in its cytoplasmic loop. The PGI2 receptor protein shares similar characteristics with TXA2 and PGE2 receptors. Molecular characterization of the prostanoid receptor will promote understanding of the roles played by these bioactive arachidonate metabolites and help developing new treatment strategies in disorders of the circulation system.