The inactivation of pregnant mares’ serum gonadotrophin by hydroquinones and quinones.

This research found that the hormones administered to pregnant mares lose their potency when exposed to certain chemical compounds, particularly when those compounds oxidize.

Understanding the Chemical Reaction

• The research is centered around pregnant mares’ serum (PMS), which contains gonadotrophic hormones. These hormones are critical for the mare’s ability to conceive and maintain pregnancy.
• When PMS is subjected to hydroquinones and quinones in an in vitro setting, it found that PMS loses its gonadotrophic activity. This reaction effectively inactivates the hormones in the serum.
• Hydroquinones, however, did not inactivate PMS unless they were first allowed to oxidize into their corresponding quinones. This suggests that the oxidation process plays a significant role in how these compounds interact with PMS.

Deeper Insights into Specific Compounds

• Of the various compounds analyzed, Þ-Benzoquinone was found to have a stronger inactivating effect on the hormones in PMS compared to mono-substituted quinones.
• In contrast, di- and tetra-substituted quinones showed little or no effect on the PMS hormone activity, indicating that not all quinones have the same potency in causing PMS inactivation.

Impact of “Humic Acid”

• Another compound evaluated was “humic acid”, an amorphous polymer formed by “ageing” p-benzoquinone solutions.
• This compound was found to partially inactivate PMS, but much less actively than its parent compound, p-benzoquinone.
• This suggests a potential mitigating effect that “ageing” p-benzoquinone solutions – and thus forming “humic acid” – could have on the inactivation process.

Implication of the Research

• These findings provide important insights into how certain compounds can impact the activity of hormones in PMS, which has significant implications for pregnant mares.
• The study suggests a need for careful consideration to prevent PMS exposure to these compounds, particularly in environments where pregnant mares are cared for.