PF-04449613 is a phosphodiesterase 9A (PDE9A) inhibitor (IC50= 22 nM).1It is selective for PDE9A over PDE1C (IC50= >1,000 nM), as well as over a variety of other PDEs, inhibiting PDE2-8, -10, and -11 activity by less than 30% in a panel of enzymes, ion channels, and transporters at 1 μM but does inhibit the human dopamine transporter (DAT; Ki= 293 nM). PF-04449613 (0.1-100 mg/kg, s.c.) increases cerebrospinal fluid (CSF) levels of cyclic GMP (cGMP) in rats. Subcutaneous administration of PF-04449613 (10 mg/kg) increases the rate of dendritic spine formation and elimination in mouse primary motor cortex pyramidal neuronsin vivo.2It increases the average running speed of mice in an accelerating rotarod task, indicating improved motor learning, at the same dose. 1.Claffey, M.M., Helal, C.J., Verhoest, P.R., et al.Application of structure-based drug design and parallel chemistry to identify selective, brain penetrant, in vivo active phosphodiesterase 9A inhibitorsJ. Med. Chem.55(21)9055-90

PDE7 inhibitor S14 is a cell-permeable PDE7 inhibitor that acts by targeting the cyclic adenosine monophosphate (cAMP)/cAMP-response element-binding protein (CREB) pathway.

PF-8380 hydrochloride 是一种有效的autotaxin 抑制剂，体外酶实验和人类全血细胞实验中，IC50分别为 2.8 nM 和 101 nM。

K134 is an inhibitor of phosphodiesterase 3. The IC50s of K134 for PDE3A, PDE3B, PDE5, PDE2 and PDE4 are 0.1, 0.28, 12.1, >300 and >300 μM, respectively.

PhosphodiesteraseII，即磷酸二酯酶 2，主要参与水解重要的第二信使环磷酸腺苷 (cAMP) 和环磷酸鸟苷 (cGMP)，常用于生化研究。PhosphodiesteraseII 表达于多种组织，如肾上腺髓质、脑、心脏、血小板、巨噬细胞和内皮细胞，可参与调节许多不同的细胞内过程。

Roflupram是一种选择性的PDE4抑制剂（IC50=26.2 nM），具有口服活性和可透过血脑屏障的优点，能够逆转认知缺陷并和抑制促炎因子产生。