Bradykinin acts on which receptor on endothelial cells?

Bradykinin is a peptide that plays a crucial role in mediating various physiological effects, particularly in inflammation and the regulation of blood pressure. It exerts its effects primarily through the bradykinin receptors located on endothelial cells, among other tissues.

The B-2 receptor is the primary receptor that bradykinin binds to on endothelial cells. This receptor is a G protein-coupled receptor that, when activated by bradykinin, leads to a series of intracellular signaling events. These events include the production of nitric oxide and prostacyclin, which promote vasodilation, enhance blood flow, and contribute to the inflammatory response. The activation of B-2 receptors is also responsible for increased vascular permeability, which is important during inflammatory reactions.

In contrast, while there are other bradykinin receptors such as the B-1 and B-3 receptors, they play different roles and are not primarily activated by bradykinin under normal physiological conditions. B-1 receptors are usually upregulated during inflammation and respond to des-Arg^9-bradykinin, a metabolite of bradykinin. The roles of B-3 and B-4 receptors are less defined in comparison, with limited or no significant involvement