Page 227 - Physiology and Pathophysiology MNU 2024-2025 نظرى

Clinical pharmacy 2024/2025 Level 2 Pharm D Physiology and Pathophysiology (MD303)
TESTOSTERONE

Testosterone is produced from the conversion of androstenedione.

• In addition to direct usage of testosterone, some target tissues convert testosterone into

dihydrotestosterone (DHT) via 5-reductase.

• Testosterone has a high binding affinity to SSBG and, & albumin.

Function:

Testosterone, DHT ➔androgen effects.

Mediated by Testosterone Mediated by Dihydrotestosterone

✓ Differentiation of epididymis, vas • Differentiation of penis, scrotum, and
deferens, and seminal vesicles prostate
Male hair pattern

✓ Increased muscle mass • Male pattern baldness

✓ Pubertal growth spurt • Sebaceous gland activity

✓ Cessation of pubertal growth spurt • Growth of prostate
(epiphyseal closure)
✓ Growth of penis and seminal vesicles

✓ Deepening of voice

✓ Spermatogenesis

✓ -Ve feedback on anterior pituitary

✓ Libido

Other effects Secretion

Tissue Effect -ve feedback to both ant.
Bone / Growth of bone (muscle) Pit. & hypothalamus. (
Muscles and connective tissue. Testosterone GnRH, LH and FSH.)

Sebaceous gland size and Stimulates Sertoli cells to
Skin
secretions. release inhibins
-ve feedback to the ant.

Inhibins
Pit ➔FSH
No role for has been
Activins
functionally determined.

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