The Ryanodine Receptor (RyR) is a class of intracellular calcium channels located primarily in the membranes of the sarcoplasmic reticulum (SR) in muscle cells. These receptors are crucial for the release of calcium ions (Ca2+) into the cytoplasm, which is essential for muscle contraction. There are three main isoforms of RyR: RyR1, RyR2, and RyR3, each with distinct tissue distribution and physiological roles.
