Biochemical pharmacology
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Biochemical pharmacology · May 1999
ReviewRegulation of ryanodine receptors by reactive nitrogen species.
The ryanodine receptors (RyRs) are large intracellular calcium release channels that play an important role in the control of the calcium levels in excitable and non-excitable cells. Many endogenous modulators such as Mg2+, ATP, or calmodulin can affect the channel activities of the three known mammalian RyR isoforms. RyRs also are known to be redox-responsive. ⋯ Both an oxidative and a nitrosative modification of RyRs have been described, leading to either a reversible or irreversible alteration of RyR ion channel activity. Additional mechanisms of regulation may include cyclic GMP-dependent signaling pathways and NO modification of RyR regulatory proteins such as the surface membrane L-type Ca2+ channel. Modification of RyRs by NO may influence a variety of physiological functions such as insulin release, vasomotor control, and muscle contraction.