Effect of 2-deoxy-D-glucose on gonadotropins, prolactin and serum glucose concentrations in the mare.

The research article investigates whether the administration of 2-deoxy-D-glucose (2DG), a glucose inhibitor, onto mares would impact the secretion of reproductive hormones. However, the research found that short-term deprivation of glucose through this inhibitor does not significantly alter the secretion of the gonadotropin hormone.

Research Background

• Glucose deprivation, or glucoprivation, has been found to suppress the reproductive system in various species.
• The authors sought to explore the effect of glucoprivation on the secretion of gonadotropin and prolactin, two hormones involved in reproduction, in mares.
• This was achieved by administrating 2-deoxy-D-glucose (2DG), a glucose inhibitor, to the mares and then monitoring any hormonal alterations.

Research Methodology

• Two experiments were conducted on long-term ovariectomized mares (i.e., mares that had their ovaries removed) and ovary-intact mares during the follicular phase of a synchronized estrous cycle.
• The mares were treated with 2DG. Initially, the dose was 100mg 2DG/kg body weight (BW), but this caused severe behavioral responses, leading to lower doses being administered in the second experiment.
• The researchers also determined the pituitary responsiveness to glucoprivation by injecting gonadotropin-releasing hormone 6 hours post treatment.

Research Findings

• No significant changes in gonadotropin secretion or pituitary responsiveness were observed in mares after the administration of 2DG.
• Mares treated with 100 mg 2DG/kg BW exhibited a significant increase in prolactin, while those treated with 100mg or 50mg 2DG/kg BW showed a significant increase in serum glucose levels, suggesting that glucoprivation was detected at these doses.
• No significant alterations in prolactin or glucose levels were found when lower doses of 2DG were used.

Conclusions

• While 2DG was confirmed to inhibit glucose utilization in mares, it was found that short-term glucoprivation did not significantly affect the secretion of gonadotropin.
• The authors suggest this lack of response may be due to species differences in reacting to glucoprivation or it may be a result of metabolic responses to reduced glucose availability.