Measurement by ELISA of equine alpha-1-proteinase inhibitor in uterine flushings from mares.

This research developed a new test to measure the levels of a specific protein called alpha-1 proteinase inhibitor (API) in the uterus of mares. The study used this test to monitor changes in API concentration during different stages of the mares’ oestrus cycle and in response to induced endometritis (inflammation of the uterine lining).

Research Methods and Results

• An enzyme linked immunosorbent assay (ELISA) was developed for the study. ELISA is an analytical tool most commonly used in medicine and plant pathology to detect the presence of an antibody or antigen in a sample. In this study, it was used to estimate API concentrations in uterine flushings (fluids recovered from the uterus).
• The researchers collected samples from mares at different stages of the oestrous cycle (oestrus and dioestrus) and before and after the induction of experimental endometritis, which is an inflammation of the endometrium, the inner lining of the uterus.
• The findings showed a significant increase in API and albumin concentrations during oestrus compared with dioestrus. Albumin is another type of protein, but unlike API, it’s mainly in charge of maintaining the osmotic pressure needed for proper distribution of body fluids between blood vessels and body tissues.
• Such increase, however, was not observed before and after the induction of endometritis, implying the fluctuations of API and albumin are not directly impacted by the induced inflammation in the uterus.
• A further regression analysis revealed a significant correlation between the concentrations of albumin and API in the samples, which led to the conclusion that the source of API in the uterus was not local, but entirely derived from the serum. Serum is the portion of the blood that includes proteins and antibodies but excludes red and white blood cells.

Implications and Applications

• This study’s results might pave the way for further exploration of the role of API during the oestrous cycle and under disease conditions. Since the concentration of API varies significantly with potential implications for fertility or disease, more insights about the dynamics of these proteins can help formulate effective treatments or fertility enhancement strategies in horse breeding.
• The newly developed ELISA could be utilized as a diagnostic tool to measure API concentration in uterine flushings and other samples, contributing to a deeper understanding of the biological processes and pathological conditions in the equine uterus.