Description:IC50 Value: 0.12 uM (ROCK1); 0.17 uM (ROCK2) [1]Hydroxyfasudil, metabolite of Fasudil, is a potent Rho-kinase inhibitor and vasodilator.in vitro: Fasudil (1-10 μM) and hydroxyfasudil (0.3-10 μM) significantly prevented endothelin-induced cardiomyocyte hypertrophy [2]. Hydroxyfasudil significantly attenuated serotonin (IC)-induced vasoconstriction of SA (-7 +/- 1% vs. 2 +/- 1%, p < 0.01). Coronary I/R significantly impaired coronary vasodilation to acetylcholine after I/R (SA, p < 0.05; and A, p < 0.01 vs. before I/R) and L-NMMA further reduced the vasodilation, whereas hydroxyfasudil completely preserved the responses.in vivo: Treatment with hydroxyfasudil significantly improved bladder intercontraction intervals. Rats treated with hydroxyfasudil also showed a significant reduction of histopathological features associated with cystitis [3]. Twelve-week-old male SHRs were treated with hydroxyfasudil (3 or 10 mg/kg, i.p.) once a day for 6 weeks. Treatment with hydroxyfasudil significantly improved the decreased penile cGMP concentrations, the increased Rho kinase activities, the increased norepinephrine-induced contractions, and the decreased acetylcholine-induced relaxation in a dose-dependent manner [4].Toxicity: The proportion of patients with good clinical outcome was 74.5% (41/55) in the fasudil group and 61.7% (37/60) in the nimodipine group. There were no serious adverse events reported in the fasudil group [5].Clinical trial: N/A