Production of endothelin-1 and big-endothelin-1 by pleural mesothelial cells.

Immunoreactive endothelin-1 (ET-1) and big-endothelin-1 (big-ET-1) were detected in conditioned medium of cultured rat pleural mesothelial cells by using sensitive sandwich-type enzyme immunoassay. The amount of both ET-1 and big-ET-1 increased time-dependently. In both instances, maximal amount was detectable in conditioned medium obtained after 72 h in culture (ET-1: 117.1 +/- 30.1 pg/10(6) cells; big-ET-1: 2.4 +/- 2.1 pg/10(6) cells). Fetal calf serum markedly stimulated the production of both ET-1 and big-ET-1.