text: PDE3 inhibitors:
  *antagonize platelet aggregation
  *block oocyte maturation
  *increase contractility of the heart
  *enhance vascular smooth muscle relaxation
  *enhance airway smooth muscle relaxation
  It has been demonstrated that PDE3A inhibition prevents oocyte maturation in vitro and in vivo. For example, when mice are made completely deficient of PDE3A, they become infertile.
  Aggregation of platelets is highly regulated by cyclic nucleotides. PDE3A is a regulator of this process, and PDE3 inhibitors effectively prevent aggregation of platelets. Cilostazol is approved for treatment of intermittent claudication and is thought to involve inhibition of platelet aggregation and also inhibition of smooth muscle proliferation and vasodilation.
  The most studied roles of PDE3B have been in the areas of insulin, IGF1, and leptin signaling. When PDE3B is overexpressed in β-cells in mice, it causes impaired insulin secretion and glucose intolerance.