Animal experiment:

Male Wistar rats weighing 300-350 g are anaesthetized with thiopental 100 mg/kg intraperitoneally (i.p.). A tracheotomy is performed and catheters are inserted into the femoral artery for blood pressure and heart rate measurements and into the femoral vein for test drug administration. The animals are ventilated with room air and their body temperature is controlled. ROCK-IN-2 is administered intravenously (i.v.) in doses of 0.03-0.1 mg/kg. The vehicle Transcutol/Cremophor EL/physiological saline (19/10/80 = v/v/v) without test drug is used as control. The volume administered is 1 mL/kg. Six animals are treated per group[1].

Azaindole 1 is an orally active and ATP-competitive ROCK inhibitor with IC50s of 0.6 and 1.1 nM for human ROCK-1 and ROCK-2, respectively. ROCK-1|0.6 nM (IC50)|ROCK-2|1.1 nM (IC50)|TRK|252 nM (IC50)|FLT3|303 nM (IC50)

Azaindole 1 is a highly potent inhibitor of human ROCK-1 and ROCK-2, with IC50s of 0.6 and 1.1 nM, respectively, and also inhibits murine ROCK-2 or rat ROCK-2 with IC50s of 2.4 and 0.8 nM, respectively. Azaindole 1 also inhibits receptor tyrosine kinases TRK and FLT3, with IC50s of 252 and 303 nM, respectively, but shows slight inhibition of MLCK and ZIP-kinase with IC50s of 7.4 μM and 4.1 μM, respectively. Azaindole 1 induces vasorelaxation in vitro, and suppresses the phenylephrine-induced contraction of rabbit saphenous artery in a concentration dependent manner with an IC50 value of 65 nM[1].

Azaindole 1 (0.03, 0.1, 0.3 mg/kg, i.v.) results in a dose-dependent and long-lasting decrease in blood pressure in anaesthetized normotensive rats. Azaindole 1 (3 and 10 mg/kg, p.o.) decreases blood pressure dose-dependently and persistently both in normotensive and hypertensive rats, and shows such effects even at 1 mg/kg in hypertensive rats. Azaindole 1 (0.1 and 0.3 mg/kg, i.v. bolus injections) causes decreased mean arterial blood pressure in a dose-related manner and only leads to a moderate and dose-independent increase in heart rate of anaesthetized dogs[1].

[1]. Kast R, et al. Cardiovascular effects of a novel potent and highly selective azaindole-based inhibitor of Rho-kinase. Br J Pharmacol. 2007 Dec;152(7):1070-80. Epub 2007 Oct 15.