THE EFFECTS OF RESERPINE PRETREATMENT ON THE D- AND L-ISOMERS OF SOME SYMPATHOMIMETIC AMINES

¹ College of Pharmacy, The Ohio State University, Columbus, Ohio

Blood pressure and nictitating membrane effects of the D- and L- isomers of norepinephrine, epinephrine, cobefrin, phenylephrine and octopamine were studied in spinal cats. The responses obtained in reserpine-treated animals were compared to those obtained in control animals. The pressor effects of D(-)-norepineophrine, L(+)-norepinephrine, D(-)-epinephrine, L(+)-epinephrine, D(-)-cobefrin, D(-)- phenylephrine, and D(-)-octopamine were mainly direct in nature, while L(+)-cobefrin, L(+)-phenylephrine, and L(+)-octopamine exhibited a considerable component of indirect activity. A similar pattern also was observed in nictitating membrane with the exception that D(-)-octopamine exhibited some indirect activity on this effector organ. The effect of spatial configuration in relation to direct and indirect action is discussed. The importance of the D-or a-configuration at the beta carbon and its relation to "direct" activity is emphasized.