Induction of B1-Kinin Receptors in Vascular Smooth Muscle Cells: Cellular Mechanisms of MAP Kinase Activation

Vascular smooth muscle cell (VSMC) proliferation is a prominent feature of the atherosclerotic process that occurs after endothelial injury. Although a vascular wall kallikrein-kinin system has been described, its contribution to vascular disease remains undefined. Because the B1-kinin receptor subtype (B1KR) is induced in VSMCs only in response to injury, we hypothesize that this receptor may be mediating critical events in the progression of vascular disease. In the present study, we provide evidence that des-Arg-bradykinin (dABK) (10 M), acting through B1KR, stimulates the phosphorylation of mitogen-activated protein kinase (MAPK) (p42 and p44). Activation of MAPK by dABK is mediated via a cholera toxin–sensitive pathway and appears to involve protein kinase C, Src kinase, and MAPK kinase. These findings demonstrate that the activation of B1KR in VSMCs leads to the generation of second messengers that converge to activate MAPK and provide a rationale to investigate the mitogenic actions of dABK in vascular injury.