Ryanodine receptors are involved in nuclear calcium oscillation in primary pancreatic β-cells

► We found that RyRs are expressed on the nuclear envelope in single primary pancreatic β-cells and isolated nuclei. ► We showed that the pattern of glucose-induced Ca2+ oscillation in the nucleus and cytosol was similar. ► Our results demonstrate that ryanodine-sensitive Ca2+ stores exist and have function in the pancreatic β-cell nucleus.