[quote]The issue is that the cells in the balding areas (especially in those follicles) make much more PGD2 than normal
[postedby]Originally Posted by walrus[/postedby]
Your answer is feasible, and this could well be the case if the majority of PGD2 synthesis is localised in the follicle itself.
But note from the Garza et al paper: ‘We also detected PTGDS outside of the hair follicle epithelium, indicating potential sources of PGD2 in the dermis’
From this we may expect dermal derived PGD2 to inhibit transplanted and non-transplanted hairs alike - which of course, doesn’t happen.[/quote]
Good point, and thanks for pointing that out. I think that most of the extra PDG2 that’s synthesized is right inside the follicle, in the follicle’s cells itself.
Some of the extra PGD2 found outside the follicles may be either from cells actually found in the tissue between follicles, or may also be “seepage” of PGD2 from the follicle.
In any event, ALL skin, all throughout the body, would be expected to have some native PGD2. PGD2 isn’t made just inside balding follicles on the scalp, it’s made throughout the whole body, especially in the skin, but also in the Central Nervous System, the brain, the heart, and other organs.
Remember, PGD2 is also part of the NORMAL hair growth cycle, even in non-balding follicles on your scalp, and even in every single person who doesn’t have MPB.
The only difference is, in the scalps of balding people, the synthesis of PGD2 is much greater than in the scalps of non-balding people.
The reason that transplanted follicles don’t (usually) miniaturize is that the small amount of PGD2 made or present in the tissues in-between balding follicles just isn’t enough to destroy the transplanted follicles.
Remember that PGD2 has a VERY short half-life after it is synthesized, maybe a few seconds. Therefore the action of PGD2 (like all prostaglandins) is VERY localized with respect to where it’s made. It can’t have an effect too far away from where it’s made. We’re talking very tiny distances.
IMO the reason an affected follicle miniaturizes but a neighboring transplanted one does not is because there is simply a non-stop flood of PGD2 being synthesized locally in the MPB follicle.
Picture a million little water faucets that are ALWAYS turned on, always gushing with water (PGD2), non-stop, from the time a follicle starts to bald until your death.
The effect is continuous and uninterrupted, but the distance of the effect from the source is very tiny, so the effect is extremely localized with respect to the source.