dht tipo 1-2 post interessante da alt.baldspot

[MathiasREX]

l'altra sera non riuscivo a prendere sonno così mi sono letto un pò di alt.baldspot...

ho trovato questo post che mi sembra essere particolarmente interessante ,parla della localizzazione del dht tipo 1 e tipo 2 nelle diverse regioni dello scalpo, dei bulbi, della papilla dermica ecc.

penso che possa darci un idea di quella che potrebbe essere la posibile efficacia di dutasteride sulla regione frontale.

 

Bryan,

 

I was searching through alt.baldspot earlier and saw a post by you

detailing a study done by Dr Sawaya on 5a-R at work in occipital and

frontal follicles. You state that she discovered that Type 1 5a-R is

40-60% more common in frontal follicles than in occipital follicles in

men suffering from MPB. And also that there is more Type 1 5-aR in

follicles of men suffering from MPB than in non-balding men or in

women.

 

Can you explain the study because you didn't quote it in your post. I

ask because in previous posts you have said that Type 2 5a-R is mostly

at work in balding follicles, and that Type 1 5-aR only enters the

equation from the sebaceous glands in the scalp and through the serum.

It seems Dr Sawaya is saying something else.

 

Pete, that's not quite what I've said in the past. Let me clarify:

 

1) I believe that type 2 5a-R is mostly at work in the dermal papilla,

the "control center" of the follicle; and I believe that's why type 2

inhibitors alone are much more effective than type 1 inhibitors

alone at stopping balding, even though there's definitely type 1

in other parts of the follicle. Furthermore, even though some recent

studies (like that Japanese study to which I referred in my email to you)

have even found mRNA for type 1 in the dermal papilla, I consider

the bottom line "acid test" to be the fact that two different groups

have now found that only tiny quantities of finasteride are sufficient

to shut down 5a-R activity in them. MK386 was ineffective.

(Also, keep in mind that cultured dermal papilla cells lose their

ability to express type 2, according to that Japanese study.

There appear to be serious differences between the "in vivo" and

"in vitro" expression of these enzymes.) I was never ever referring

to the follicle as a WHOLE as having only type 2 at work. Just the

dermal papilla.

 

 

Here are a few selected passages from Sawaya's "Different Levels

of 5a-Reductase Type I and II, Aromatase, and Androgen Receptor

in Hair Follicles of Women and Men with Androgenetic Alopecia":

 

"...Establishing the optimum assay conditions resulted in finding

differences in the isoenzymes in scalp hair follicles, as shown in

Table III, in which type I is four to five times higher than type II

in both women and men. Both isoenzyme forms were significantly

higher (p<0.001) in frontal than occipital follicles for women and men.

Women had approximately 3 to 3.5 times less type I and II 5a-R,

respectively, than hair follicles of men.

 

"When comparing frontal to occipital hair follicles within women, results

indicate approximately 40% more type I and type II isoenzymes in frontal

than occipital follicles (p<0.001). Frontal follicles in men had approximately

60% higher levels of both isoenzymes than occipital follicles (p<0.001).

The results indicate clear differences between as well as within women

and men with regard to frontal versus occipital hair follicles.

 

Table III. Type I and II 5a-R Levels in Hair Follicles

from Women and Men*

-------------------------------------------------------

5a-R

-------------------------

Type I Type II

-------------------------------------------------------

Women

Frontal HF 22.0 +/- 2.8 4.6 +/- 2.0

Occipital HF 13.0 +/- 1.8 2.8 +/- 1.0

 

Men

Frontal HF 63.3 +/- 2.2 17.2 +/- 1.4

Occipital HF 29.4 +/- 2.2 6.9 +/- 1.4

 

*Activity expressed as pmol per 30 min per 0.5 mg protein.

 

And here is a little bit from the "Discussion" section:

 

"Other studies have emphasized the importance of type I 5a-R found

in skin (Itami et al, 1990, 1991) versus type II 5a-R in prostate and testes

(Anderson et al, 1991; George et al, 1991). The current study indicates

that both forms of 5a-R may be present in scalp hair follicles. In AGA,

the levels of these two isoenzymes may differ in frontal and occipital

scalp hair follicles....It was recently shown in whole skin sections that

5a-R type 1 is expressed strongly in sebaceous glands and hair follicles,

whereas 5a-R type II is expressed in the dermal papilla and interfollicular

dermal spindle cells (Russell et al, 1996)..."

[MathiasREX]

[Salusmaster]

Io rimango sempre convinto dell'importanza di inibire anche il tipo I di 5ar....

 

E' un'opinione personale, ma nell'attesa di dutasteride, vediamo cosa combina il saw palmetto

[supcap]

Completamente d'accordo con Salus! Anch'io confido in SAW PALMETTO nel frattempo di DUTA. Però salus la mia situazione è più critica rispetto alla tua, io sono un hamilton 3 mentre tu un 1, penso che quello che c'è in giro ora per te basti mentre per me è solo un mantenimento...per recuperare quello perso io devo sudarne di camicie!!!

[tristan]

...si ma perke ci hanno sempre mostrato nelle foto di duta la parte posteriore dello scalpo????? ....

 

cccccciiiiiiiiaaaaaaaaaaooooooooo

[avalon76]

Ciao Salus,tu parli saw palmetto come

sostituto di duta.

Cos'e' questo saw palmetto???

Si compra in farmacia???