NPPB and hydrops fetalis: In rat heart, during angiotensin II-induced HF, there is an increase in the hydrolytic activity of PDE1 with respect to cGMP (+130%), mRNA of PDE1A (+140%), and PDE1C (+54%) and protein expression of PDE1A (+30%) and PDE1C (+32%; +41%) associated with an increase in BNP mRNA expression (+254%) [109].