Y-39983 dihydrochloride is a novel and selective inhibitor of ROCK family with IC50 value of 3.6nM for ROCK.

Y-39983 dihydrochloride has shown a selective inhibitor of Rho-associated coiled coil-forming protein kinase( ROCK ) with IC50 values of 3.6nM, 0.42μM and 0.81μM for ROCK, PKC and CaMKII, respectively . Apart from these, Y-39983 has been reported to relax the ciliary arteries of precontracted isolated rabbit in vitro. In addition, Y-39983 has been found to increase optic-nerve-head blood flow by laser speckle flowmetry [2]. Moreover, Y-39983 lowered the intraocular pressure ( IOP) in a dose-dependent fashion in the eyes of rabbits and monkeys .