Here is an interesting study I just ran across. Current thought is that hairs on the back and sides of our heads, commonly referred to the "horse shoe" are immune to the effects of DHT and thereby are used in our hair transplants. But now a study has been presented that notes this may not be the case. Though they are more resistant to DHT than hair in the commonly lost regions they are not totally immune. If they are subjected to sufficient quantities of these hormones, they too will miniaturize and die. Just when we thought we were safe!

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Skin Pharmacol Physiol. 2006;19(6):311-21. Epub 2006 Aug 23. Links
Effect of 5alpha-dihydrotestosterone and testosterone on apoptosis in human dermal papilla cells.
Winiarska A,
Mandt N,
Kamp H,
Hossini A,
Seltmann H,
Zouboulis CC,
Blume-Peytavi U.
Department of Dermatology and Allergy, Charite-Universitatsmedizin Berlin, Berlin, Germany.


Pathogenetic mechanisms in androgenetic alopecia are not yet fully understood; however, it is commonly accepted that androgens like testosterone (T) and 5alpha-dihydrotestosterone (5alpha-DHT) inhibit hair follicle activity with early induction of the catagen. Thus, we investigated the influence of T and 5alpha-DHT on proliferation, cell death and bcl-2/bax expression in cultured dermal papilla cells (DPC) from nonbalding scalp regions of healthy volunteers. T and 5alpha-DHT induced apoptosis in DPC in a dose-dependent and time-related manner; in addition a necrotic effect due to T at 10(-5) M was found. Interestingly, bcl-2 protein expression was decreased in T- and 5alpha-DHT-treated cells, leading to an increase in the bax/bcl-2 ratio. In addition, T and 5alpha-DHT induced proteolytic cleavage of caspase 8 and inhibited proliferation of DPC at 10(-5) M. High concentrations of T and 5alpha-DHT were needed to induce apoptotic effects in DPC. These data suggest that DPC from nonbalding scalp regions do have the capacity to undergo apoptosis, but need a high androgen stimulus. The present study provides an interesting new pathogenetic approach in androgenetic alopecia.

Very interesting....but I'd say we are still pretty "safe" because the majority of people do not lose hair in their backs and sides, though admittedly, over time, with age, sometimes it does thin, but I haven't seen anyone (except cancer patients) lose all their hair in these regions. But the research is definitely interesting...unfortunately, not in our favor.

Falc

I wouldn't lose sleep over it either Falc, but I did see it happen to one guy once. He had lost his the "normal" amount of hair during his 20's and 30's, had a hairpiece made up to cover it in his 40's.
When he hit his 50's, he started losing the so called resistant areas. This guy eventually ended up with a "whole head hairpiece". I guess if that happens, we may be able to turn to BHT as an alternative???

You know that good old Murphy's Law.

The majority of balding men I see seem to also have thinning donor regions.

Very few are completely bald in the donor area so you won't lose more than half the transplanted hair in all likelihood.

Still not a pleasant thought! Hate to go through all of this and end up with a thinning look again. Guess nothing is forever, especially our hair.

Sheesh, Cousin!! Here I was thinking the chrome dome was behind me for good.

Seriously.....good post but as has already been posted "odds are" that the transplanted donor hair will be with the vast majority of us for life. (hope I'm in that majority )

Maybe I should have posted this after the holidays, don't want to kill anyones festive moods!