title: Prostacyclin synthetic activity in cultured aortic endothelial cells undergoing cyclic mechanical deformation.
abstract: The effect of mechanical stretching on prostacyclin (PGI2) synthesis was studied by growing bovine aortic endothelial cells on flexible-bottomed culture plates that could be deformed by vacuum. A stress unit was used to exert an elongation of 24% at maximum downward deflection of the culture plate bottom. The experimental group was subjected to cycles of 10 seconds of elongation, 10 seconds of relaxation for 1, 3, or 5 days. The control group was subjected to similar incubations but without cyclic stretch. Twenty-four hours before collection, the medium was replaced with new medium that was devoid of serum. On days 1, 3, and 5, the 24-hour culture medium was collected (basal state). Arachidonic acid (20 mumol/L) was then added to each culture and incubated for 5 minutes at 37 degrees C. The medium was then collected to assess prostacyclin synthetic activity (stimulated state). Media were assayed for PGI2 and thromboxane A2 by radioimmunoassays for 6-keto-PGF1 alpha and thromboxane B2, the respective stable hydrolysis product. The results indicate that cyclic stretching, while not altering the basal production of PGI2, increases PGI2 synthetic capacity in a time-dependent manner. These data suggest that it may be inappropriate to extrapolate the mechanisms of in vivo PGI2 release from studies of endothelial cells in stationary culture.
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism*; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D002417:Cattle; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000378:metabolism*; D011464:Epoprostenol / Q000096:biosynthesis*; D010507:Periodicity; D013314:Stress, Mechanical; D013931:Thromboxanes / Q000096:biosynthesis; D013997:Time Factors
chemical_list: D001095:Arachidonic Acids; D013931:Thromboxanes; D016718:Arachidonic Acid; D015121:6-Ketoprostaglandin F1 alpha; D011464:Epoprostenol