Calcium-induced calcium release of CICR across the cell causes the significant increase in cytosolic Ca that is important in activating muscle contraction. Calcium-induced calcium release Calcium-induced calcium release (CICR) describes a biological process whereby calcium is able to activate calcium release from intracellular Ca stores (e.g., endoplasmic reticulum or sarcoplasmic reticulum). Although CICR was first proposed for skeletal muscle in the 1970s, it is now known that CICR is unlikely to be its primary mechanism for activating SR calcium release. Instead, CICR is thought to be crucial for excitation-contraction coupling in cardiac muscle and it is now obvious that CICR is a widely
Calcium sulfide lime, Ca(OH), reacts with elemental sulfur to give a "lime-sulfur", which has been used as an insecticide. The active ingredient is probably a calcium polysulfide, not CaS. Calcium sulfide decomposes upon contact with water, including moist air, giving a mixture of Ca(SH), Ca(OH), and Ca(SH)(OH). It reacts with acids such as hydrochloric acid to release toxic hydrogen sulfide gas. Oldhamite is the name for mineralogical form of CaS. It is a rare component of some meteorites and has scientific importance in solar nebula research. Burning of coal dumps can also produce the compound. Calcium sulfide Calcium sulfide is the chemical