For instance, instead of using drugs to block the release or uptake of various drugs or neurotransmitters, scientists could change the electricity regulating the
ion pump, which would then change the amount of the drug or molecule inside, or outside, the cell.
In physiological conditions cytosolic calcium level is controlled by the balance between calcium influx and efflux by ion channels, ATP-dependent
ion pumps, buffers such as calbindin-D28 k, parvalbumin (3, 4).
The most important neural activity is the changing of membrane potential of a neuron, which depends on the work of
ion pumps. Among these pumps, the [Na.sup.+]/[K.sup.+] pump is the most crucial one and it consumes most of the metabolic energy.
Chemists describe experimental methods for resolving the kinetics and dynamics of
ion pumps, channels, and transporters in proteins.
ELECTRIFYING APPEAL Levin acknowledges that his theory doesn't explain how normal left-right asymmetry gets started: Something has to first distribute [H.sup.+]/[K.sup.+]-ATPase and other
ion pumps and channels unevenly.
Many other
ion pumps have since been discovered, including the enzymes responsible for muscle contraction and the production of stomach acid.
Systems of this sort could potentially serve as models of cellular
ion pumps and biomolecular motors (SN: 3/22/97, p.