13,14-dihydro-PGE1, an in-vivo metabolite of PGE1, decreases mitotic activity induced by corticosteroid administration.

PGE1 has antimitotic activity by virtue of its effect in increasing cAMP in vascular smooth muscle cells. The present study compares the effect of 13,14-dihydro-PGE1 (13,14-DH-PGE1) with PGE1 in an experimental model of stress induced by desoxycorticosterone in the rabbit. 13,14-DH-PGE1 significantly inhibited the stress-induced increase in mitotic activity, measured by autoradiography as percentage of 3H-thymidine positive cells, in all 3 abdominal aortic wall layers. Administration prior to stress was more effective than after stress, while combined administration was most effective. 13,14-DH-PGE1 exerts approximately 90% of the antimitotic activity of PGE1. It seems possible that the antimitotic activity observed after administration of intravenous PGE1 is attributable in part to 13,14-DH-PGE1.