Module 7: Figure RYR2 location in cardiac cells
The distribution of ryanodine receptor 2 (RYR2) in atrial and ventricular cells.
A. Immunolocalization of ryanodine receptor 2 (RYR2) in atrial myocytes. The RYR2s are located in two main areas: immediately below the sarcolemma, where they have a punctate appearance (shown more clearly in the higher magnification image A,b) and as non-junctional RYRs that run in parallel strands. B. In the ventricular myocyte, the RYR2s are located in junctional regions on the T-tubules that invade the interior of the cell. Note the staining of the perinuclear region (PR) surrounding the nuclei. A diagram illustrating the localization of RYR2 is shown in Module 7: Figure ventricle and atrial cell organization. Reproduced from MacKenzie, L., Bootman, M.D., Berridge, M.J. and Lipp, P. (2001) Predetermined recruitment of calcium release sites underlies excitation-contraction coupling in rat atrial myocytes. J. Physiol. 530:417–429, with permission from Blackwell Publishing; see MacKenzie et al. 2001.