Epinephrine yields translocation of lymphocytes to the lung

Previous studies have demonstrated that acute stress leads to the appearance of T-lymphocytes in skin and bone marrow. In order to examine the effects of adrenergic stimulation on the traffic of immune lymphocytes to the lung, C57BL/6 mice were injected with epinephrine subcutaneously, and changes in lymphocyte representation in lung, hilar lymph node, spleen, and blood were examined at 30 min. Cytofluorimetric lymphocyte subset analysis showed that epinephrine increased "memory" CD4+ lymphocytes in enzymatic digests of lung but decreased their representation in spleen. NK1.1+ lymphocytes were concomitantly increased in lung and decreased in spleen. Next, lymphocytes in spleen or popliteal lymph nodes were labeled with the Hoechst lipophilic red dye PKH26 in vivo 48 h prior to epinephrine injection. PKH26+ lymphocytes were identified in lung tissue at 30 min postepinephrine but not in controls. Lymphocyte traffic was inhibited by propanolol. We conclude that epinephrine promotes rapid shifts in immune lymphocytes from lymphoid tissues into lung and blood. Directed traffic of immune lymphocytes may be a feature of the adaptive immune response to stress at mucosal barrier surfaces.