NCIt definition : The hydrochloride salt of hydralazine, a phthalazine derivative with antihypertensive
and potential antineoplastic activities. Hydralazine alters intracellular calcium
release and interferes with smooth muscle cell calcium influx, resulting in arterial
vasodilatation. This agent also inhibits the phosphorylation of myosin protein and
chelation of trace metals required for smooth muscle contraction, resulting in an
increase in heart rate, stroke volume and cardiac output. In addition to its cardiovascular
effects, hydralazine inhibits DNA methyltransferase, which may result in inhibition
of DNA methylation in tumor cells.;