PTGER1 and congenital diaphragmatic hernia: Although there was no difference in expression of prostaglandin-I2 synthase (Ptgis) between control and CDH rat pups, there was a slight increase in the expression of Ptgir and the prostaglandin-E1 receptor (Ptger1) in CDH at the mRNA level in both the whole lung as well as compared to the number of smooth muscle cells.