Antithrombotic activity of a new P2Y1 receptor antagonist, substance Sbt-119, on experimental models of thromboses in rats.

Antithrombotic properties of a new P2Y1 receptor antagonist N-[(1-morpholinopropyl-amino)- carbonyl-2-(1-ethyl-1H-indole-3-yl)-vinyl]-4-methylphenyl-amide hydrochloride, substance Sbt-119, and reference drug ticlopidine were studied on experimental models of arterial and systemic thromboses. Substance Sbt-119 was 39.9% (p<0.05) more potent than ticlopidine in producing the antithrombotic effect. Moreover, substance Sbt-119 was shown to increase the survival rate of animals after systemic treatment with ADP (by 20%, p<0.0001). This substance decreased the number of mural thrombi and reduced the severity of hemodynamics disturbances in the organs during systemic thrombosis.

In vitro method of studying the angiotensin activity of chemical compounds.

We developed and tested an experimental model to study in vitro the type 1 angiotensin antagonistic activity of compounds on the isolated portal vein of rats. The reliability of this method was confirmed in tests with saralasin (nonselective antagonist of angiotensin receptors) and losartan (selective antagonist of type 1 angiotensin receptors) in concentrations of 10(-9)-10(-5) mol/liter. The half-maximal inhibitory concentrations (IC50) of these substances were calculated.

Effect of 5-HT(2A) receptor antagonists on blood flow in the carotid vessels upon elevation of serotonin level.

We studied the ability of predominantly 5-HT2A receptor antagonists to prevent a serotonin-induced change of blood flow in the carotid vessels of rats with experimental serotonin-induced spasm. Ritanserin, ketanserin, and 5-HT2A receptor antagonist RU-476 reduced the effect of serotonin on the blood fl ow velocity in the internal carotid artery by 2.3, 1.7, and 2.6 times, respectively.