Haemodynamic and Antihypertensive Effect of Prostacyclin

Abstract

Prostacyclin (2) is a natural product of blood vessels, synthetized predominantly in endothelium and released in minute amounts into circulation (3). Besides its potent antiplatelet activity (1,4, 6), prostacyclin is also a powerful vasodilator. The vasodilating properties were noticed already during first administration of prostacyclin to man (7), and were subsequently studied in detail in 10 subjects without evidence of coronary heart disease or cardiac failure (11, 12). Prostacyclin was infused in three dose levels (2, 5 and 10 ng/kg/min) leading to following effects:

• 1) Distinct fall in peripheral and total pulmonary vascular resistances;

• 2) Drop in intra-arterial blood pressure;

• 3) Acceleration of the heart rate;

• 4) Increase in muscle blood flow;

• 5) Stroke volume, mean right atrial pressure and left ventricular end-diastolic pressure showed no significant changes.