Serum levels of progesterone, 5 alpha-dihydroprogesterone and hydroxy-5 alpha-pregnanones in the prepartum and postpartum equine.

This research paper examines the levels of certain hormones, specifically progesterone, 5 alpha-dihydroprogesterone and hydroxy-5 alpha-pregnanones, in the blood of horses before and after giving birth. The findings indicate variability in the levels of these hormones at different stages of birth.

Research Methodology

• The blood samples for this study were collected from eight mares ten days before and two days following parturition, which is the process of giving birth.
• The hormones of interest, namely progesterone, 5 alpha-dihydroprogesterone and hydroxy-5 alpha-pregnanones, were extracted from the serum of these blood samples. The process of extraction was facilitated through Sephadex LH-20 column chromatography.
• The quantity of these hormones was determined using a test known as radioimmunoassay, which is a sensitive method to measure the concentration of antibodies using radioactive substances.

Key Findings

• The serum levels of progesterone ranged from 8.5 ng/ml to 4.1 ng/ml in mares with normal childbirth and decreased to 1.2 ng/ml after giving birth. One mare maintaining prepartal levels of progesterone into the postpartum period had a retained placenta, a potentially life-threatening condition where the placenta remains in the uterus after birth.
• Levels of 5 alpha-dihydroprogesterone, a derivative of progesterone, increased to a level of 133 ng/ml about 80 hours before birth. Following birth, these levels started to decrease, reaching a level of 9.2 ng/ml after parturition.
• Hydroxy-5 alpha-pregnanones levels showed variability, with a peak level of 1690 ng/ml. After birth, the levels of this hormone declined to 60 ng/ml. The timing of the decline wasn’t consistent across all the mares.

Implications of the Study

• This research provides valuable insight into hormonal fluctuations in mares during the birthing process. The exact source and significance of the hormones investigated in this study, however, are still unclear and remain an avenue for further research.
• The findings could serve as a preliminary guide for monitoring the hormonal changes in pregnant mares, which could potentially contribute to better care and management of mares during pregnancy and childbirth.
• The study could potentially kickstart further research into how these specific hormones affect the reproductive cycles and health of equines, and whether they can be used as biomarkers for predicting or intervening in birthing complications.