this use has advantages over the use of inorganic di- and trivalent cations such as mg2+ , mn2+ , cd2+ , ni2+ , la3+ , etc. , since the latter , though they are considered to be the most specific competitive antagonists of calcium ions , may induce biphasic effects due to their ability to cross the membranes and replace calcium and/or increase intracellular calcium concentration .
C0007447
cations
C0022023
ions