Proteins associated with the early intrauterine equine conceptus.

This research study investigates the proteins associated with early stages of horse pregnancy and compares the proteins found in normal pregnancies with those in pregnancies that are artificially terminated. The study found that the failure of a pregnancy is linked with an increase in specific proteins in the embryonic capsule and a change in protein forms in the uterus.

Research Goal

The purpose of the study was to compare the main proteins in a normal horse embryo around the time of fixation — the point at which the embryo becomes immobile, approximately 16-17 days after conception — and those found in pregnancies artificially terminated by use of a prostaglandin analogue, PGF(2 alpha).

Comparison of Proteins

• Two proteins associated with the embryonic capsule, uterocalin and beta(2)-microglobulin (beta(2)M), were examined.
• The researchers observed that these proteins were converted into smaller forms during the fixation period, indicating an alteration in the structure and function of these proteins as the pregnancy progresses.
• This conversion occurred similarly in both normal pregnancies and ones that were artificially terminated.

Identification of New Protein

• A 17 kDa cationic protein, identified as secretory phospholipase A2 (sPLA2) type IIA, was found in normal embryonic capsules but its concentration significantly increased in response to induced pregnancy termination.

Detection of Uteroglobin Forms

• Two forms of uteroglobin were identified from fluids flushed from the uterus of normal pregnancies.
• Following the administration of the termination agent (PGF(2 alpha)), the researchers observed an increase in one of the uteroglobin forms, which suggests a response to the termination process.

Conclusion

The research highlights that an increase in secretory phospholipase in the embryonic capsule and a change in the forms of uteroglobin in the uterine secretions are indicative of a failed pregnancy. These findings could potentially aid in the early detection or prevention of pregnancy failure in horses.