Notes: Hydroxyprogesterone caproate is a synthetic progestogen.{39556} In vivo, hydroxyprogesterone caproate (3.32 mg/kg) reduces TNF-α-induced hypertension and decreases renal endothelin-1 (ET-1) production in pregnant rats. It reduces hypertension and production of TNF-α and IL-6 induced by reduction in uteroplacental perfusion (RUPP) in pregnant rats.{39557} Hydroxyprogesterone caproate also prevents preterm birth induced by L-NAME (Item No. 80210) in pregnant mice.{39558} Formulations containing hydroxyprogesterone caproate have been used for the prevention of preterm birth.