Prostaglandin (PG) E1 and 13,14-dihydro (DH) PGE1 are diminishing radiation-induced arterial damage.

Rabbit abdominal aorta was irradiated with single or repeated doses up to 10 Gy. The rabbits were killed at different time intervals after irradiation. 5 micrograms/kg x 6/hr PGE1 or its biologically active metabolite 13,14-DH-PGE1 were administered either 6 hours before or 6 hours after irradiation. The administration of both PGEs reduced radiation-induced mitotic activity (3H-thymidine incorporation) and extracellular matrix [collagen-(14C-proline) and glycosaminoglycan (35-S-sulphate)]-formation as determined by means of autoradiography. The initial peak increase in vascular PGI2-synthesis was partly abolished, while the long lasting depression was less pronounced. 13,14-DH-PGE1 was only slightly less active as compared to the parent compound. Pre-radiation treatment was more effective than post-irradiation therapy. These findings suggest that both the PGs exert significant radiation-protective actions on the arterial wall.