Catecholamines and dopamine-beta-hydroxylase activity during therapeutic abortion induced by sulprostone

To evaluate the changes in circulating norepinephrine (NE), epinephrine (E) and dopamine-beta-hydroxylase (DBH) caused by an intravenous infusion of a derivate of PGE2, sulprostone, in connection with legal termination of pregnancy, serial plasma samples were analyzed for six gravidae. Plasma catecholamines were measured by a sensitive radioenzymatic method (9,10) and DBH activities by a photometric assay (11). Intravenous infusion of sulprostone, in abortifacient doses as an intravenous infusion of 3-4 microgram per minute for six to eight hours produced a decrease in circulating norepinephrine. No significant alteration was found in plasma epinephrine or dopamine-beta-hydroxylase activity. The finding suggests an inhibitory effect of sulprostone on the release of norepinephrine from the adrenergic terminals without inhibition of the adrenal medulla.