How NMN enters your cells, quickly and effectively ?
If we could deliver NAD+ directly into cells, we probably would. Why can’t we ? Because the molecule itself is too big. NMN, a slightly smaller molecule, is the next best thing. It’s just a step away from becoming NAD+.
The Baseball Glove
There is a recently discovered way, that NMN gets into cells potentially within a matter of minutes. It seems to have its own dedicated receptionist. Shaped rather like a baseball glove.
Solute Carrier Family 12 Member 8, aka SLC12A8, is a very special member of the solute carrier (SLC) family of membrane transporter proteins, which, in turn, are members of the major facilitator superfamily. So, it keeps good company. These are all responsible for ushering a different nutrients into cells, while simultaneously ensuring there isn’t a door left open for unwanted guests.
Anyway, shaped like a baseball glove, SLC12A8 receives water in the cavity of its palm. From that water, NMN sticks to the lining of the glove, and then, effectively gets squeezed directly through into the cell. No need for NR, in this case. As a matter of fact, SLC12A8 refuses to talk to NR, waiting patiently for its NMN.
Right place, right time
Interestingly, there is a lot of SLC12A8 exactly where you would want it, precisely in the small intestine - up to a hundred times more there than in other parts of the body - making it ripe and ready for the quick uptake of NMN. More studies are currently being done on SLC12A8, as a promising line of further scientific research.