Effect of prolonged administration of anabolic and androgenic steroids on reproductive function in the mare.

The research explores the impact of long-term use of anabolic and androgenic steroids on reproductive functionality in mares. The researchers found that traditional doses of the steroid methandriol did not significantly affect reproductive attributes, aside from suppressing basal LH levels. However, elevated doses of the steroid or high-dose testosterone resulted in notable changes, including aggressive behavior resembling that of stallions and complete reproductive shutdown after a month.

Objectives and Methodology of the Research

• The goal of this research was to discover what impact, if any, the long-term use of anabolic and androgenic steroids had on the reproductive function of mares. The two steroids utilized in this study were the anabolic steroid methandriol and testosterone.
• Mares were given methandriol at the recommended highest dose for one and a half years, while others received four times that amount. The researchers compared the results to those of a control group.
• With testosterone, mares received small, moderate, and large doses. Large doses were intended to elevate plasma testosterone to levels seen in stallions.

Findings of the Research

• The standard dosage of methandriol (300 mg every three weeks) had little impact on reproductive features, except for the suppression of LH (luteinizing hormone) release that GnRH (gonadotropin-releasing hormone) triggers.
• When the dosage of methandriol was quadrupled, it suppressed basal LH, the LH surge, and GnRH-related LH release. However, other reproductive responses showed minimal difference.
• Weight changes and behavioural effects were not observed among methandriol-administered mares when compared with matched control mares.
• Small and moderate doses of testosterone led to changes in behavior, but did not affect reproductive function.
• However, when large doses of testosterone were given (equivalent to levels in stallions), they caused a complete suppression of all reproductive activity within a month, as well as the development of aggressive, stallion-like behavior. This effect ceased within a month after the treatment was stopped.

Conclusion of the Research

• The research suggests that prolonged use of steroids can have significant effects on mares, particularly with elevated doses. It implies that steroid dosages should be cautiously managed to avoid potential reproductive and behavioral disruptions.