Composition for prophylaxis or treatment of pulmonary circulatory diseases

摘要

Cyclic hexapeptides having antagonistic activity on endothelin receptors of the formula [I]: <IMAGE> [I] wherein X and Y each is an alpha -amino acid residue having D-, L-form or DL-form, A is a D-acidic- alpha -amino acid residue, B is a neutral- alpha -amino acid residue having D- or L-form, C is an L- alpha -amino acid residue and E is a D- alpha -amino acid residue having an aromatic ring group can be effectively used for prophylaxis and/or treatment of pulmonary circulatory diseases./!