α₁-Adrenoceptor Subtypes and α₁-Adrenoceptor Antagonists

Abstract

  α₁-adrenoceptors are widely distributed in the human body and play important physiologic roles. Three α₁-adrenoceptor subtypes (α_1A, α_1B and α_1D) have been cloned and show different pharmacologic profiles. In addition, a putative α₁-adrenoceptor (α_1L subtype) has also been proposed. Recently, three drugs (tamsulosin, naftopidil, and silodosin) have been developed in Japan for the treatment of urinary obstruction in patients with benign prostatic hyperplasia. In this review, we describe recent α₁-adrenoceptor subclassifications and the pharmacologic characteristics (subtype selectivity and clinical relevance) of α₁-adrenoceptor antagonists.