PTGER1 and aneurysm: Disruption of EP1 receptor results in decreased mean arterial pressure, lessened aneurysm severity and the absence of anasarca, and a significant decrease in the incidence of mortality was observed in EP1+/+ but not EP1−/− mice, implicating that disruption of the EP1 receptor has a protective effect on end-organ damage (44).In some vascular beds, the pressor activity of EP1 receptor is implicated in the smooth muscle contractile response to PGE2.