Due to its highly hydrophilic amphipathic ionic structure, it is
difficult for EGT itself to cross the phospholipid bilayer of the
cell membrane.EGT can be transported via a specialized
protein, OCTN-1.
✓ OCTN-1 is a powerful sodium-driven plasma membrane
uptake transporter. In all vertebrates, the ability to uptake,
distribute and retain EGT is entirely dependent on the
expression of this highly specific transporter. Cells lacking
OCTN-1 do not actually accumulate EGT. In humans, EGT is
strongly expressed only in certain cells and tissues: erythroid
progenitors of the bone marrow, intestine, kidney, trachea,
cerebellum and monocytes.
✓ Although OCTN-1 is a cationic transporter, its rate of transport
of EGT is 100-fold higher than that of other transported
substrates (e.g., TEA and carnitine);
✓ Oxidative stress-induced tissue damage increases the
expression of OCTN-1.The more OCTN-1 is expressed, the
more EGT accumulates in the cells of that tissue, i.e., the more
EGT can intelligently get to the places where it is needed.EGT
continues to accumulate in damaged tissues, but does not over-
accumulate in healthy and normal tissues.
