Suppressive effect of catecholamines on 19-S antibody formation in mouse spleen fragments in vitro

Spleen fragments of Balb/C mice were immunized with sheep red blood cells in vitro and hemolytic plaque forming cells (PFC) were assayed on the 5th day of immunization. Epinephrine in culture medium diminished the number of PFC dose-dependently over the range from 10(-6) M to 2.7 X 10(-4) M. Incubation with 9 X 10(-5) M epinephrine diminished PFC response only when the epinephrine was present on the first day of the culture. No suppression was found for treatment during any other 24-hr periods. Three beta-adrenergic stimulating catecholamines, epinephrine, isoproterenol, and norepinephrine, suppressed PFC response in similar degree. It is concluded that beta-adrenergic stimulation suppressed 19-S antibody formation mainly by inhibiting induction of immune response.