Imidazoline I1 receptor (I1 receptor)

The Imidazoline I1 receptor is a cell-surface binding site primarily located on the plasma membrane of neurons within the rostral ventrolateral medulla, as well as in other tissues such as adrenal medulla, renal epithelium, pancreatic islets, platelets, and prostate. It plays a key role in inhibiting sympathetic nervous system activity to lower blood pressure. The I1-imidazoline receptor is distinct from alpha2-adrenoceptors but shares some pharmacological overlap; it mediates the antihypertensive actions of drugs like moxonidine and rilmenidine by decreasing sympathetic tone centrally. Activation leads to signal transduction involving diacylglycerol production via phosphatidylcholine-selective phospholipase C. Beyond its established role in cardiovascular regulation—especially hypertension—the I1-imidazoline receptor may also influence metabolic processes such as insulin secretion and glucose tolerance. Its molecular identity has been linked with IRAS/Nischarin proteins but remains incompletely defined at the gene/protein level. The target continues to be explored for therapeutic applications beyond hypertension due to its involvement in broader physiological processes including inflammation, neuroprotection, cell proliferation, and possibly psychiatric conditions.[1][2][3][4][5][6]

Other names

I1-imidazoline receptorI1 binding siteImidazoline receptor subtype 1

Agonists lower blood pressure by inhibiting central sympathetic outflow through activation of the I1-imidazoline receptor in the rostral ventrolateral medulla, leading to vasodilation and reduced peripheral vascular resistance[2][4][5].