Prostaglandin E1 decreases the low-density-lipoprotein entry into rabbit arterial wall.

1. In 72 male rabbits fed a 1% cholesterol supplemented diet the effect of a 4 weeks daily infusion of prostaglandin E1 (PGE1, 20 micrograms kg-1 min-1 over 2 h) on [125I]-low density lipoprotein (LDL) accumulation (10 microCi; 0.5 mg protein ml-1) was examined versus sham-treatment after removal of the endothelium of the abdominal aorta by a Fogarthy catheter. 2. The uptake of [125I]-LDL was significantly (P less than 0.01) higher in endothelium-free aortic segments (showing the highest peak maximum at around 12 h after 125I-injection) as compared to aortic segments with endothelium intact (showing the lowest uptake of [125I]-LDL with the peak maximum at 48 h, last control time). Segments with the endothelium restored showed a similar LDL-retention curve to segments with endothelium however, being again significantly (P less than 0.01) higher. 3. PGE1-treatment caused reduction in LDL-accumulation, being significantly (P less than 0.001) pronounced in segments without endothelium and in segments with endothelium restored. 4. The findings indicate a beneficial effect of PGE1 in lipid metabolism by decreasing the LDL-influx into the arterial wall in-vivo.