Piriprost is a structural analog of PGI2 with low IP receptor-mediated activity. Piriprost inhibits 5-LO with an IC50 value around 100 μM, as measured by the release of 5-HETE from cultured myometrial cells.{994} Piriprost inhibits the release of histamine and leukotrienes from isolated porcine lung cells with an IC50 value of 0.11 μM.{4708}