Endogenous prostaglandin F2 alpha release induced by physiologic saline solution infusion in utero in the mare: effect of temperature, osmolarity, and pH.

The research article focuses on investigating the effects of temperature, osmolarity and pH of saline solution on the release of prostaglandin F2 alpha (PGF2 alpha) and luteolysis in mares. Results show that pH played a significant role in provoking PGF2 alpha, with temperature and osmolarity having no impact on its release.

Research Methodology

• Thirty mares with normal estrous cycles were divided into five groups and Infused with 250 ml of saline (NaCl) solution in utero on the seventh day after ovulation.
• Each group was subjected to varying conditions of temperature, osmolarity, and pH and the influence these factors had on prostaglandin F2 alpha (PGF2 alpha) release and luteolysis were observed.
• Some of the specific conditions included: maintaining normal temperature, increasing temperature to 42°C, increasing or decreasing osmolarity (600 mosm or less than 10 mosm respectively) and decreasing the pH of saline solution to 3.

Key Findings

• The study found that decreasing the pH of saline solution to 3 caused a significant release of PGF2 alpha from the uterus within the first hour after infusion.
• The luteal phase duration, a part of the estrous cycle, was also affected and shortened to 8.8 +/- 1.0 days, compared to the control group’s 15 +/- 1.2 days.
• In contrast, intrauterine infusion of phosphate-buffered saline solution, increasing the temperature to 42 C or altering the osmolarity did not affect the duration of the luteal phase.

Conclusion

• The results concluded that pH is the major factor triggering the release of PGF2 alpha with saline solution infusion in the uterus.
• In contrast, changes in temperature and osmolarity seemed to have no effect on the release of PGF2 alpha.
• The research thus adds to the larger body of scientific knowledge concerning the induction of estrus in mares, a technique that has been in use for the past 50 years.