[Modulation of endothelin-1 on pulmonary surfactant synthesis in lung explants]

The effect of endothelin-1(ET-1) on pulmonary surfactant(PS) synthesis was studied in cultured lung explants without serum. The results showed that: 1. ET-1 increased [3H] choline incorporation with dose-dependence and time-dependence. 10(-10) mol.L-1 ET-1 increased the contents of total phospholipids, phosphatidylcholine and phosphatidylglcerol in lung tissues. The major membrane characteristic phospholipids, such as phosphatidylethanolamine, phosphatidylinostitol, phosphatidylserine and sphingomyelin, did not show changes. 2. BQ123, a ETA receptor selective antagonist, could decline the [3H] choline incorporation induced by ET-1(10(-12) and 10(-10) mol.L-1) (P < 0.01). 3. PMA, a protein kinase C(PKC) activator, increased [3H] choline incorporation into lung tissues (P < 0.01); the PKC inhibitor H7 decreased [3H] choline incorporation induced by ET-1(P < 0.01). The results demonstrated that ET-1 at physiological level can enhance the PS synthesis mediated by ETA receptor and PKC.