Nj. Birch, LITHIUM IONS HAVE LIMITED INTRACELLULAR ACCESS - IMPLICATIONS FOR CELL REGULATION AND PHARMACOLOGY, Journal of trace and microprobe techniques, 12(1-2), 1994, pp. 1-16
Lithium is absorbed into the body via a paracellular route in the inte
stinal mucosa. This route is also followed by other metals and the tru
e function of 'transport proteins' identified for some metals is quest
ioned. Lithium concentrations in cells, determined by NMR and AAS tech
niques are lower than usually assumed, often no more than 10% of the e
xternal concentration. This has implications for the cellular actions
of lithium in therapy and its postulated mode of action. A hypothesis
is proposed for an integrative and regulatory role of metals associate
d with the cell membrane. It is suggested that those metals which are
embedded in, and interacting with, the largely insulating lipid and gl
ycolipid layers of the cell membrane might regulate charge movements i
n the membrane in a manner analagous to metal particles in a silicon m
icrochip. The concept is suggested of the 'biomicrochip', based on the
cell membrane and with infinitely variable architecture for cellular
integration and regulation.