Thromboxane synthetase inhibition as antithrombotic strategy

Area of Science:

• Biochemistry
• Pharmacology
• Cardiovascular Research

Background:

• Thromboxane A2 (TXA2) is a potent pro-aggregatory agent implicated in thrombosis.
• Prostacyclin (PGI2) is an anti-aggregatory agent that counterbalances TXA2.
• Thromboxane synthetase inhibitors offer a potential therapeutic strategy to modulate these eicosanoids.

Purpose of the Study:

• To investigate the in-vitro and in-vivo effects of the thromboxane synthetase inhibitor UK-37 248.
• To evaluate the potential of UK-37 248 as an antithrombotic agent.

Main Methods:

• In-vitro studies using washed platelets and cultured endothelial cells.
• A double-blind, placebo-controlled study in human volunteers.
• Measurement of thromboxane B2 and 6-keto-prostaglandin F1 alpha levels.
• Assessment of platelet aggregation induced by arachidonic acid and adenosine-5'-diphosphate.

Main Results:

• UK-37 248 inhibited in-vitro thromboxane B2 formation and increased prostaglandin E2 and F2 alpha production.
• In vivo, UK-37 248 reduced serum thromboxane B2 and increased plasma 6-keto-prostaglandin F1 alpha.
• Complete inhibition of arachidonic acid-induced platelet aggregation was observed, while adenosine-5'-diphosphate-induced aggregation remained unaffected.

Conclusions:

• UK-37 248 effectively inhibits thromboxane synthetase, shifting the balance towards anti-aggregatory prostacyclin.
• Thromboxane synthetase inhibitors, by reducing TXA2 and increasing PGI2, may represent a more effective antithrombotic strategy than aspirin.