Imidazoline-1 receptor (I1-IBS)

The Imidazoline-1 receptor (I1-IBS) is a non-adrenergic receptor primarily located in the rostral ventrolateral medulla (RVLM) of the brainstem, where it plays a central role in cardiovascular regulation [1, 2]. It was first identified as a distinct binding site for imidazoline-containing drugs like clonidine, separate from alpha-2 adrenergic receptors [5, 6]. Activation of I1-IBS by selective agonists, such as moxonidine and rilmenidine, reduces sympathetic outflow from the central nervous system, effectively lowering blood pressure and heart rate with fewer sedative side effects than traditional alpha-2 agonists [1, 6]. The molecular identity of the I1-IBS is widely associated with the protein Nischarin (NISCH), also known as IRAS (Imidazoline receptor antisera-selected protein) [6, 8]. Beyond its role in hypertension, I1-IBS is involved in metabolic processes, including insulin secretion, and has been implicated in the pathophysiology of depression and chronic pain [2, 7].

Other names

I1 imidazoline receptorImidazoline-1 binding siteI1RNischarinNISCHImidazoline receptor antisera-selected proteinIRAS

Agonists stimulate I1 receptors in the rostral ventrolateral medulla (RVLM), which inhibits sympathetic nervous system activity, leading to a decrease in peripheral vascular resistance and blood pressure [1, 6].