FIGURE 31. Epoxyeicosatrienoic acids (EETs) induced relaxation and hyperpolarization of vascular smooth muscle cells.

FIGURE 31

Epoxyeicosatrienoic acids (EETs) induced relaxation and hyperpolarization of vascular smooth muscle cells. Some neurohumoral mediators, such as bradykinin, and shear stress activate the metabolism of arachidonic acid (AA) via cytochrome P450 monooxygenase (P450). Epoxyeicosatrienoic acids (EETs) are endothelium-derived relaxing and hyperpolarizing substances activating large conductance calcium-activated (BKCa) or ATP-sensitive (KATP) potassium channels via ADP-ribosylation of Gsα. The stimulation of the latter involves adenylate cyclase (AC) and the production of cyclic adenosine monophosphate (cAMP). Additionally, the activation of BKCa can be indirect via the heme oxygenase (HO) and the generation of carbon monoxide (CO) or via the calcium-signaling complex, transient receptor potential channel vanilloid 4 (TRPV4)—ryanodine receptors (RyR) and the generation of calcium sparks. Furthermore, EETs can modulate endothelial responses by producing superoxide anion (O2.-) and by regulating the intracellular calcium concentration, potassium channel activity and gap junctional communications. B2: bradykinin B2 receptor subtype; DAG: diacylglycerol; Glib: glibenclamide; IbTX: iberiotoxin; IKCa: intermediate conductance calcium-activated potassium channel; PLA2: phospholipase A2; PLC: phospholipase C; SOC: store operated channel; SR: sarcoplasmic reticulum; TRPC: canonical transient receptor potential channel; SKCa: small conductance calcium-activated potassium channel.

From: Chapter 4, Endothelium-Dependent Regulation of Vascular Tone

Cover of The Endothelium
The Endothelium: Part 1: Multiple Functions of the Endothelial Cells—Focus on Endothelium-Derived Vasoactive Mediators.
Félétou M.
San Rafael (CA): Morgan & Claypool Life Sciences; 2011.
Copyright © 2011 by Morgan & Claypool Life Sciences Publishers.

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