Heterogeneity of sperm density profiles following 16-week therapy with continuous infusion of high-dose LHRH analog plus testosterone

Area of Science:

• Reproductive Endocrinology
• Male Contraception Research
• Hormonal Regulation

Background:

• Luteinizing hormone-releasing hormone (LHRH) agonists are explored for male contraceptive potential.
• Previous studies show reversible oligozoospermia with LHRH agonist [D-Trp6,Pro9-NEt] LHRH (LHRHA) and testosterone enanthate, but with variable individual responses.

Purpose of the Study:

• To evaluate the efficacy and hormonal effects of continuous LHRHA infusion combined with testosterone enanthate in normal male volunteers.
• To investigate if continuous infusion improves upon variable results seen with single-dose administration.

Main Methods:

• Eight healthy males received a continuous infusion of 500 µg/day of LHRHA for 16 weeks.
• Testosterone enanthate (100 mg) was administered intramuscularly every two weeks.
• Hormone levels (FSH, LH, testosterone) and sperm counts were monitored throughout the study and after discontinuation.

Main Results:

• Six out of eight subjects achieved oligozoospermia (sperm count < 20 million/ml).
• Two subjects showed no significant decrease in sperm count, indicating variable response.
• Continuous LHRHA infusion led to pituitary desensitization, suppressed bioactive LH, decreased FSH and testosterone levels.
• All measured parameters returned to baseline after cessation of LHRHA treatment.

Conclusions:

• Continuous LHRHA infusion with testosterone enanthate induces hormonal suppression and reduces sperm counts in most men.
• Significant inter-individual variability in response persists, with some men not achieving sufficient sperm suppression.
• The continuous infusion method did not overcome the heterogeneity in sperm density profiles observed previously.