Anti-thromboxane activity in Rhodnius prolixus salivary secretion

The salivary secretion of Rhodnius prolixus inhibits arachidonic acid-induced platelet aggregation and the accompanying rabbit aorta-contracting activity. Results are presented that show antagonism to thromboxane A₂ on both platelet aggregation and rabbit aorta preparations. The antagonist is heat stable, non degradable by pronase, non dialysable and is sensitive to periodate oxidation.A brief review of the pharmacological properties of Rhodnius saliva is presented. It is suggested that Rhodnius prolixus developed salivary anti-haemostatic components that allows them to take a large meal in a short time.