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

An enzyme linked immunosorbent assay (ELISA) was developed and used to estimate the concentrations of the serine proteinase inhibitor, alpha-1 proteinase inhibitor (API), in uterine flushings recovered from mares at different stages of the oestrous cycle and before and after the induction of experimental endometritis. There was a significant increase in the concentrations of API and albumin relative to total protein in flushings recovered during oestrus compared with dioestrus but no difference was observed in the concentrations of these proteins relative to total protein before and after the induction of endometritis. A regression analysis revealed a significant correlation between the concentrations of albumin and API in the flushings examined, suggesting that the API was derived entirely from serum and was not produced locally in the uterus.