研究人员发现血管壁分泌的prostacyclin能有效防止血栓形成。

Researchers found that ___prostacyclin secreted by blood vessel walls effectively prevents blood clot formation.

医生建议使用前列环素来缓解她的肺动脉高压症状。

The doctor recommended ___prostacyclin to relieve her pulmonary hypertension symptoms.