Testosterone vs DHT

[Dr.Stein]

Time has come for Dr.Stein to ask question!!! Please reply soon

I know that DHT (dihydrotestosterone) comes after testosterone (T) is catalyzed by 5-alpha-reductase. Both T and DHT has SIMILAR receptor, but DHT fits more properly to the receptor rather than T, thus it is said that DHT is "activated" T.

However, from their function, it is stated that they have specific targets, for instance that DHT mainly affects on skin and genital (externa), while T mainly affects in spermatogenesis, spermatozoa maturation/capasitation, responsible in the appearance of secondary sex characteristics (virilisation) and anabolic effects.

My question is: What thing does make this specificity of their target cells/tissues? Say, a cell with T's receptor can bind DHT too, right? Vice versa, a cell with DHT's receptor can bind T. That's because they have similar receptor. But how skin is specific to DHT and not to T as well? Maybe there is a "secondary signal" after the receptor:ligand complex-action, in the same way like when T-cell making a cognate interaction with APC, for instance, that beside T-receptor the cell needs certain marker to have a fix binding? Or something else? Do I miss a thing here? Grr... I am so curious

Thank you for your help

[Dr.Stein]

None answers me?

[nugget]

You know what you should look into? the XY condition where boys are born being insensitive to androgens, so they cannot use DHT, but because of the high surge of TTN during puberty they become a male after the age of 12. I dont know if that helps, but thats where you might find your answer. I would think they have different receptors thats why one has affect and the other doesnt, but during development - normally, TTN doesnt have as much of an affect in determining the male sex as DHT does, thats why the amount of TTN is not enought to make them be born with female characteristics, however at puberty TTN's effect is much more profound because theres much more of it.

Does that make any sense? thats how i guess i interpreted it.

=)