Indenopyride derivative RTI-4587-073(l): a candidate for male contraception in stallions.

This research study aimed to test the contraceptive effects of the compound RTI-4587-073(l) on male horses without influencing their sexual behavior. The results showed that a single dose of the compound led to a significant reduction in sperm count and motility, which was fully reversible after around 71 days, without changing the animal’s sexual behavior.

Research Objective

• The primary goal of this research was to evaluate the effectiveness of the indenopyridine derivative RTI-4587-073(l) as a potential candidate for male contraception in horses.
• To ensure the product would not negatively impact the horses’ life, the study aimed to assess whether this compound would affect the sexual behavior of the stallions.

Methodology

• The researchers administered a single dose of the compound (12.5 mg/kg) orally to three miniature horse stallions (labelled as the “treated” group).
• For comparison, three other miniature horse stallions were given a placebo (forming the “control” group).
• The study collected and evaluated semen from all stallions twice weekly for three weeks before the treatment and 13 weeks following the treatment.
• Sexual behavior was recorded and analyzed throughout this period.
• Two sets of testicular dimensions were recorded: one before the treatment and the other during the post-treatment period.
• Blood samples were also drawn for endocrine evaluation.

Results

• The single administration of RTI-4587-073(l) caused severe oligoasthenozoospermia (low sperm count and low motility) in the treated stallions, which resulted in a large number of immature germ cells in their semen. This indicates that the compound was effective in inhibiting testicular functionality.
• An increase in FSH (follicle-stimulating hormone) concentrations was also noted in the treated stallions, further signalling the impact of the compound on their reproductive system.
• All these impacts were, however, found to be reversible within approximately 71 days.
• The sexual behavior of the horses, including libido and copulatory behavior, remained unchanged by the treatment, validating the researchers’ hypothesis and essential criteria that the contraceptive should not affect the sexual behavior of the animals.

Conclusion

• Given the results, the research concludes that RTI-4587-073(l) is a promising candidate for male contraception in domestic stallions.
• In the light of these findings, the study suggests further research to test the potential of this compound for fertility control in wildlife and even humans.