Testosterone and 5 alpha-dihydrotestosterone concentrations in human seminal plasma

Area of Science:

• Reproductive Endocrinology
• Andrology
• Clinical Chemistry

Background:

• Seminal plasma hormone levels, specifically testosterone and dihydrotestosterone (DHT), are crucial indicators of male reproductive health.
• Previous research has explored the origins and significance of androgens in seminal fluid, but a clear distinction between fertile and infertile samples regarding DHT remains an area of interest.

Purpose of the Study:

• To investigate and compare the concentrations of testosterone and dihydrotestosterone (DHT) in the seminal plasma of fertile and infertile human males.
• To determine the potential correlation between altered seminal DHT levels and specific infertility conditions such as azoospermia and oligozoospermia.

Main Methods:

• Radioimmunoassay (RIA) was employed to quantify testosterone and DHT levels in human seminal plasma samples.
• Semen samples were categorized based on fertility status, including fertile, azoospermic, and oligozoospermic groups.

Main Results:

• Testosterone concentrations did not significantly differ between fertile and infertile semen samples.
• Dihydrotestosterone (DHT) concentrations were found to be significantly lower in seminal plasma from azoospermic and oligozoospermic individuals compared to fertile controls.
• A notable decrease in DHT was observed in patients with severe sperm count abnormalities.

Conclusions:

• Testosterone in seminal plasma primarily originates from the accessory sex glands.
• Dihydrotestosterone (DHT) in seminal plasma is predominantly of testicular or epididymal origin.
• The reduced DHT levels in infertile men, particularly those with azoospermia and oligozoospermia, likely result from a defective epididymal conversion of testosterone to DHT, highlighting a potential mechanism for male infertility.