Protective action of 6-keto-prostaglandin E1 in traumatic shock.

Since prostaglandin E1 (PGE1) is known to have a beneficial effect in hemorrhagic shock, a biologically active derivative of PGE1, 6-keto-PGE1, was examined for its effect on traumatic shock in rats. In sham-operated rats, infusion of 6-keto-PGE1, at a rate of 250 ng/kg/min intravenously decreased arterial blood pressure by 23 mm Hg at 5 hr. In rats subjected to Noble-Collip drum trauma, infusion of 6-keto-PGE1, starting 15 min after the trauma, significantly improved the survival time from 1.0 +/- 0.1 to 2.6 +/- 0.3 hr compared to rats given only the vehicle (i.e., Tris buffer). The improved survival was accompanied by a diminished plasma accumulation of the cardiotoxic peptide, myocardial depressant factor (MDF), and the lysosomal protease cathepsin D. 6-keto-PGE1 also exerted a direct lysosomal stabilizing effect in isolated cat liver lysosomes, as well as reducing cardiac afterload in rats. It is concluded that 6-keto-PGE1 protects in traumatic shock by hemodynamic as well as cytoprotective actions.