Nitrendipine-stimulated release of prostacyclin-like substance in normal and atherosclerotic animals.

Nitrendipine (Bayotensin) is a dihydropyridine derivative that appears to preferentially dilate peripheral vessels by a cellular mechanism similar to those found with other calcium blocking agents. In this study nitrendipine when infused (0.2-0.3 mg/kg i.v.) into anaesthetized cats caused a release of a substance disaggregating platelet clumps which had adhered to blood superfused collagen strip. The appearance of this unstable disaggregating substance was prevented by the pretreatment of cats with acetylsalicylic acid (50 mg/kg i.v.). In atherosclerotic rabbits nitrendipine stimulated release of prostacyclin-like substance without effect on proaggregatory concentrations of arachidonic acid and adenosine diphosphate. In rats nitrendipine inhibited the development of atherosclerotic changes in the aorta evoked by the atherogenic diet with ergocalciferol (vitamin D2). It is suggested that nitrendipine may promote formation of prostacyclin in arteries and inhibit the development of atherosclerosis.