Short-term mode of secretion of equine chorionic gonadotrop in and the effect of GNRH.

The authors of this research aimed to understand how equine chorionic gonadotropin (eCG) is secreted in pregnant Quarterhorse mares and whether a hormone called gonadotropin releasing hormone (GnRH) has any impact on eCG concentrations.

Research Methodology

• To investigate the secretion of eCG, the authors took blood samples from five pregnant mares every 30 minutes for 25 hours on the 50th day of their pregnancy.
• To examine the effect of GnRH, a gonadotropin releasing hormone, on eCG concentrations, the authors took blood samples from three other mares who had persistent endometrial cups after having an abortion. These mares were given GnRH injections, and their blood was sampled at 15-minute intervals up to 240 minutes post injection.

Findings on Secretion of eCG

• The researchers found that eCG concentrations in the blood plasma of pregnant mares were constant over the given 24-hour period.
• The variation in eCG concentrations in individual mares was not significantly higher than the predicted random variation of the radioimmunoassay, a common laboratory technique used to measure the concentration of hormone in blood samples.

Findings on Effect of GnRH

• The study revealed that the administration of GnRH didn’t significantly affect eCG concentrations in mares with persistent endometrial cups within a 4-hour period.

Conclusion

• The observations from this research suggest that the secretion of eCG in pregnant mares is not regulated on a short-term basis. Instead, it’s influenced by factors that affect the number of healthy endometrial cup cells in the uterus.
• This implies that hormonal treatments or interventions like GnRH may not have a significant impact on eCG concentrations or affect short-term secretion.