Hydroxyfasudil hydrochloride

Biological Activity

In vitro: Hydroxyfasudil prevents the downregulation of endothelial NO synthase (eNOS) under hypoxic conditions. In a concentration-dependent manner, hydroxyfasudil increases eNOS mRNA and protein expression, resulting in a 1.9- and 1.6-fold increase, respectively, at 10 μmol/L (P<0.05 for both). This correlates with a 1.5- and 2.3-fold increase in eNOS activity and NO production, respectively (P<0.05 for both). Hydroxyfasudil also inhibits various chemoattractant-induced migration of neutrophils. Hydroxyfasudil potently inhibits Rho-kinase (IC50, 0.9 ± 1.8 μM), while its inhibitory eff€ect is markedly (at least 50 ± 100 times) less for myosin light chain kinase (MLCK) or protein kinase C (PKC).

In vivo: Intracoronary administration of hydroxyfasudil(HF) causes a significant coronary vasodilation of both small arteries and arterioles in a dose-dependent manner under control conditions with a resultant increase in CBF(coronary blood flow). Intracoronary hydroxyfasudil does not significantly alter mean aortic pressure or heart rate. Pretreatment with hydroxyfasudil markedly reduces the I/R-induced myocardial infarct size, and this beneficial effect of hydroxyfasudil is significantly attenuated by L-NMMA. NO may be involved in those cardiovascular protective effects of hydroxyfasudil. Hydroxyfasudil may also be effective for the treatment of pulmonary hypertension. HF protects the myocardium subjected to pacing-induced ischaemia through the increase in the regional myocardial blood flow.

Protocol

Cell Experiment
Cell lines	Human vascular endothelial cells
Preparation method	Human vascular endothelial cells are treated with increasing concentrations of hydroxyfasudil (0.1 to 100 μmol/L) and eNOS expression and activity are measured.
Concentrations	0.1 to 100 μmol/L
Incubation time	18 h

Animal Experiment
Animal models	Mongrel dogs
Formulation	Physiologic saline
Dosages	10, 30, and 100 μg/kg
Administration	IC（Intracoronary administration）

Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)

Species	Mouse	Rat	Rabbit	Guinea pig	Hamster	Dog
Weight (kg)	0.02	0.15	1.8	0.4	0.08	10
Body Surface Area (m2)	0.007	0.025	0.15	0.05	0.02	0.5
Km factor	3	6	12	8	5	20

Animal A (mg/kg) = Animal B (mg/kg) multiplied by	Animal B Km
	Animal A Km

For example, to modify the dose of Compound A used for a mouse (20 mg/kg) to a dose based on the BSA for a rat, multiply 20 mg/kg by the K_m factor for a mouse and then divide by the K_m factor for a rat. This calculation results in a rat equivalent dose for Compound A of 10 mg/kg.

Chemical Information

References

[1] Holmström F, et al. Prostate. Protective effect of hydroxyfasudil, a Rho kinase inhibitor, on ventral prostatic hyperplasia in the spontaneously hypertensive rat.

[2] Shimizu N, et al. Int J Urol. Effects of the Rho kinase inhibitor, hydroxyfasudil, on bladder dysfunction and inflammation in rats with HCl-induced cystitis.