Learning Objective
Understand how LH, FSH, and sex steroids change in various clinical scenarios and how these alterations affect spermatogenesis and reproductive function.
Hormonal Changes in Specific Altered States
| Condition | Sex Steroids | LH | FSH |
|---|---|---|---|
| Primary hypogonadism (Noonan/Klinefelter syndrome) | ↓ | ↑ | ↑ |
| Pituitary hypogonadism | ↓ | ↓ | ↓ |
| Kallmann (↓ GnRH) | ↓ | ↓ | ↓ |
| Anabolic steroid therapy (male) | ↑ | ↓ | (↓) |
| Androgen insensitivity syndrome (AIS) | ↑ | ↑ | ↑ |
| Inhibin infusion (male) | − | − | ↓ |
| GnRH infusion (constant rate) | ↓ | ↓ | ↓ |
| GnRH infusion (pulsatile) | ↑ | ↑ | ↑ |
Activity
Notes:
- Anabolic steroid therapy: LH suppression causes Leydig cell atrophy and reduced testicular androgen production. High circulating testosterone also suppresses FSH, impairing spermatogenesis.
- Inhibin infusion: Suppresses FSH, reducing spermatogenesis.
- GnRH infusion: Constant infusion initially increases LH and FSH, but sustained infusion leads to receptor downregulation and decreased secretion.
