SUMMARY
The most important stage of development of effective and safe new medicines is the methods of preclinical evaluation of their pharmacological activity. Since the existing range of antihypertensive medicines is large enough and the current demands for them are different from those presented se-veral years ago, the aim of this research is to study the effect of the chemopyrone substance on the arterial pressure under conditions of prophylactic application on the experimental model of hypertension induced by Mesatonum. While studying the effect of the chemopyrone substance in the dose of 10 mg/kg on the level of systolic and diastolic arterial pressure it has been determined that the antihypertensive effect is achieved due to the impact on the function of the kidneys. The maximum effect is observed on the 10-th min and equals 64-62% compared to the group of intact animals. The results obtained testify the expressed and prolonged hypotensive effect, and the substance can be recommended for hypertensive states correction in the conditions of prophylactic application.