K134 is a phosphodiesterase 3 ( PDE3 ) inhibitor. The IC 50 s of K134 toward PDE3A , PDE3B , PDE5 , PDE2 and PDE4 are 0.1, 0.28, 12.1, >300 and >300 µM, respectively. In Vitro K134 (K-134) inhibits rat platelet aggregation induced by collagen and ADP in a dose-dependent manner in vitro. The half-maximal (50%) inhibitory concentration (IC 50 ) values of K134 are 2.5 µM and 3.2 µM, respectively. In vitro experiments, K134 also inhibits mouse platelet aggregation induced by collagen and ADP in a dose-dependent manner, and the IC 50 s are 5.5 µM and 6.7 µM, respectively. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo K134 (K-134) significantly prolongs middle cerebral artery (MCA) occlusion time at doses >10 mg/kg, and reduces cerebral infarct size at 30 mg/kg in the stroke model (n = 12, 87.5±5.6 vs. 126.8±7.5 mm 3 , P Form:Solid IC50& Target:IC50: 0.1 µM (PDE3A), 0.28 µM (PDE3B), 12.1 μM (PDE5)