Alpha-1A and alpha-1D adrenergic receptors (ADRA1A/ADRA1D)

The alpha-1A and alpha-1D adrenergic receptors are members of the G protein-coupled receptor (GPCR) superfamily that mediate the effects of the endogenous catecholamines epinephrine and norepinephrine (UniProt P35348, P25100). The alpha-1A subtype is the predominant receptor mediating smooth muscle contraction in the human prostate, bladder neck, and urethra, while the alpha-1D subtype is involved in bladder muscle function and sensory signaling in the spinal cord (StatPearls, 2023). Pharmacological targeting of these specific subtypes is a primary strategy for managing benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). By selectively antagonizing alpha-1A and alpha-1D receptors, drugs like tamsulosin and silodosin promote smooth muscle relaxation in the prostate and bladder, thereby improving urinary flow (PubMed, PMID: 16091634). This selectivity profile is clinically significant because it minimizes interaction with the alpha-1B subtype, which is primarily responsible for regulating vascular tone and blood pressure, thus reducing the risk of orthostatic hypotension and other cardiovascular side effects (PubChem). However, use of these agents is associated with specific risks, such as Intraoperative Floppy Iris Syndrome during cataract surgery and ejaculatory dysfunction.

Other names

Alpha-1A adrenoceptorAlpha-1D adrenoceptorAlpha-1A/D selective adrenergic receptorsADRA1AADRA1D

Selective antagonism of alpha-1A and alpha-1D adrenergic receptors