Ca2+ release from the envelope of isolated pancreatic acinar nuclei could be activated by nicotinic acid adenine dinucleotide phosphate (NAADP) as well as by inositol 1,4,5-trisphosphate (IP3) and cyclic ADP-ribose (cADPR). Each of these agents reduced the Ca2+ concentration inside the nuclear envelope, and this was associated with a transient rise in the nucleoplasmic Ca2+ concentration. NAADP...

We review here briefly the essentials of vertebrate cardiac pacemaking system consisting populations ion channels that drive heartbeat. In addition to sarcolemmal system, there is a second channel-based oscillator centrally reciprocating Ca2+ flow between sarcoplasmic reticulum and cytosol regulated by release through ryanodine receptors active return Sarcoplasmic/Endoplasmic Reticulum Calcium ...

Abstract Ca 2+ sparks constitute the fundamental units of release in cardiomyocytes. Here we investigate how ryanodine receptors (RyRs) collectively generate these events by employing a transgenic mouse with photoactivated label on RyR2. This allowed correlative imaging RyR localization, super-resolution localization microscopy, and sparks, high-speed imaging. Two populations were observed: sta...

Ortho-substituted polychlorinated biphenyls (PCBs) have been shown to alter microsomal Ca transport by selective interaction with ryanodine receptors (RyRs) of muscle sarcoplasmic reticulum (SR) and brain endoplasmic reticulum. The mechanism underlying the actions of PCBs on Ca transport is further elucidated with skeletal SR enriched in Ry1R. Disruption of the association between immunophilin ...

We examined whether Ca(2+) induced Ca(2+) release through ryanodine receptors is involved in the conditioning of specific morphologic changes at the axon terminals of type B photoreceptors in the isolated circumesophageal ganglion of Hermissenda. Calcium chelation by bis(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid prevented the conformational change at the terminals after five paired pres...