Effects of flunixin meglumine on endotoxin-induced prostaglandin F2 alpha secretion during early pregnancy in mares.

The research is focused on understanding the role of prostaglandin F2 alpha (PGF2 alpha) in embryonic loss in response to induced endotoxemia in early pregnant horses. The study specifically finds out the extent to which flunixin meglumine, an anti-inflammatory drug, can inhibit the production of PGF2 alpha triggered by Salmonella typhimurium endotoxin.

Objective and Methodology of the Research

• The study aims to understand how prostaglandin F2 alpha (PGF2 alpha) contributes to embryonic loss in horses suffering from induced endotoxemia – a toxic reaction caused by the release of bacterial endotoxin into the bloodstream.
• 13 mares (female horses), in their early pregnancy stages (21 to 44 days), were studied. The researchers induced endotoxemia in these mares using Salmonella typhimurium endotoxin and treated them with an anti-inflammatory drug, flunixin meglumine, hoping to curb the PGF2 alpha synthesis triggered by the endotoxin.
• The mares were divided into groups, with each group receiving flunixin meglumine at a different time – before endotoxin injection (group 1, -10 min; n = 7), and at 1 and 2 hours after the endotoxin injection (group 2, 1 hour, n = 3; group 3, 2 hours, n = 3). Additionally, there was a control group, group 4, which was given only the endotoxin without the anti-inflammatory drug.

Key Findings of the Research

• The researchers observed a biphasic PGF2 alpha secretion pattern in the control group (group 4), with two peaks – one at 30 minutes and a larger one approximately 105 minutes after the endotoxin was administered.
• When flunixin meglumine was administrated at -10 minutes before endotoxin injection, the synthesis of PGF2 alpha was inhibited for several hours. When the drug was given at 1 hour, it blocked the second surge of PGF2 alpha. However, administering the drug at 2 hours did not have a significant effect on PGF2 alpha secretion.
• Also, it was noted that the plasma progesterone concentrations didn’t change significantly after endotoxin injections in group 1. In group 2, the progesterone values decreased a bit and remained low for several days. In groups 3 and 4, the progesterone concentrations decreased sharply to values less than 0.5 ng/ml by 48 hours after the injections.

Importance of the Study

• This study helps shed light on the potential pathways of embryonic loss in horses suffering from endotoxemia and the complex molecular events associated with it.
• It also helps to understand the potential therapeutic benefits and timing of using an anti-inflammatory drug, flunixin meglumine, to treat endotoxemia in horses. It’s relevant for ensuring the safe pregnancies of mares and for the overall well-being and livelihood of horse populations at large.
• Additionally, the research suggests that further investigation and development of therapeutics that manipulate PGF2 alpha production and action could be beneficial in treating and preventing endotoxemia-induced embryonic losses.