PQ-10 is a potent and selective inhibitor of phosphodiesterase type 10 (PDE10; Ki = 4 nM). It has >38-fold selectivity for PDE10 over a panel of 60 CNS-associated receptors, enzymes, and ion channels in vitro. Subcutaneous injection of PQ-10 (32 mg/kg) leads to increases in striatal cGMP and phosphorylation of cAMP response element binding protein (CREB) in murine striatum, known markers of in vivo PDE10 inhibition. PQ-10 at a dose of 0.3 mg/kg, p.o., reduces scopolamine- and MK-801-induced memory deficits in rats. PQ-10 also inhibits tumor cell growth with IC50 values of 0.29 and 0.22 mM for HCT116 and SW480 colon cancer cells, respectively.
