Testosterone regulates keratin 33B expression in rat penis growth

[KiNGTyreZe]

Full PMC Article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4236322/

Abstract

Androgen therapy is the mainstay of treatment for the hypogonadotropic hypogonadal micropenis because it obviously enhances penis growth in prepubescent microphallic patients. However, the molecular mechanisms of androgen treatment leading to penis growth are still largely unknown. To clarify this well-known phenomenon, we successfully generated a castrated male Sprague Dawley rat model at puberty followed by testosterone administration. Interestingly, compared with the control group, testosterone treatment stimulated a dose-dependent increase of penis weight, length, and width in castrated rats accompanied with a dramatic recovery of the pathological changes of the penis. Mechanistically, testosterone administration substantially increased the expression of androgen receptor (AR) protein. Increased AR protein in the penis could subsequently initiate transcription of its target genes, including keratin 33B (Krt33b). Importantly, we demonstrated that KRT33B is generally expressed in the rat penis and that most KRT33B expression is cytoplasmic. Furthermore, AR could directly modulate its expression by binding to a putative androgen response element sequence of the Krt33b promoter. Overall, this study reveals a novel mechanism facilitating penis growth after testosterone treatment in precastrated prepubescent animals, in which androgen enhances the expression of AR protein as well as its target genes, such as Krt33b.

 

[bushbush]

If this translates to humans---one reason not to jump on finasteride at a young age (before finished growth).

Since androgens are well known to be responsible for secondary sexual characteristics, it is no surprise that their manipulation could affect penis morphology.

 

[Vlatch]

Nothing new here, that's why people aren't prescribed finasteride before they are 18.

 

[benjt]

But finasteride should increase Testosterone levels due to less conversion to DHT, or what am I missing here?

 

[KiNGTyreZe]

Read the full PMC article.

 

[benjt]

I did, but the few sentences mentioning DHT made no connection to the role of testosterone on penile growth.

 

[KiNGTyreZe]

I did, but the few sentences mentioning DHT made no connection to the role of testosterone on penile growth.

Did you read this part?

Overall, a normal penis length/size depends critically on androgens, but how androgens mediate this process is still unclear.Physically, testosterone is converted into 5α-dihydrotestosterone (DHT) by the enzyme delta4-3-ketosteroid-5α-redudase (5α-reductase), which binds to a specific androgen receptor (AR) protein. This steroid receptor complex translocates into the cell nucleus and initiates gene transcription, thus resulting in the expression of androgen target genes, which may play critical roles not only in the prostate, but also in penis growth.

 

[abcdefg]

I would pass on the penis growth and the T levels to just have hair instead personally. Also rats are quite a jump from people. There are large lists of mouse/rat studies where results didnt translate over to people so I wouldnt take this as divine word or something.