Male Sex Steroids (Androgens)

Question 1

Describe Testicular Anatomy?

Answer 1

a. LH → Leydigcells → testosterone → (negativefeedbackonhypothalamus) → inhibition of GnRH release.
b. GH is synergistic with LH to increase the synthesis of testosterone

Question 2

What increases Sex-Hormone binding globulin(SHBG)?

Answer 2

estrogen, thyroid hormone, pts with cirrhosis

Question 3

What decreases Sex-Hormone binding globulin(SHBG)?

Answer 3

androgen and growth hormone, and in obese pts.

Question 4

What is Androgen Binding Protein (ABP)?

Answer 4

i. Similar in structure to SHBG
ii. Binds testosterone in order to keep its intratesticular levels high
iii. FSH → Sertoli Cells → production of ABP

Question 5

What is the metabolism of testosterone?

Answer 5

Testosterone in liver → androstenedione → andosterone

Question 6

Which are the Synthetic Androgens that can be used orally?

Answer 6

Methyltestosterone
Fluoxymesterone (has intrinsic aromatase –blocking activity)