AT1 receptors as mechanosensors.

G-protein-coupled receptors are appreciated as central components of neurohormonal signaling. Recently, it turned out that they may also play a role in mechanotransduction. The angiotensin II AT(1) receptor was the first G-protein-coupled receptor claimed to be a mechanosensor. In the meantime, several other G(q/11)-coupled receptors were found to be sensitive to mechanical stimuli. Furthermore, there is first evidence to support the concept that G(i/o)-coupled receptors are susceptible to mechanical stimulation as well. Mechanical receptor activation appears to be agonist-independent and is initiated by a conformational change of the receptor protein discernible from agonist-bound conformations. Mechanically induced receptor activation plays a physiological role for myogenic vasoconstriction and is involved in the pathogenesis of cardiac hypertrophy.