EDN1 and infection: Measurement of endothelin-1 by enzyme-linked immunosorbent assay (ELISA) - ET-1 levels were determined in mouse serum samples collected on day 14 of infection/treatment, and 24 h supernatants from HMEC-1 cultures, using the corresponding Quantikine ELISA Kit (R&D Systems, Abingdon, UK), according to the manufacturer’s guidelines.