INVIVO NORMOBARIC OXYGEN EXPOSURE DEPRESSES SPLEEN-CELL INVITRO CON-A RESPONSE - EFFECTS OF 2-MERCAPTOETHANOL AND PERITONEAL-CELLS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 58  (2) , 428-435
Abstract
Normobaric O2 exposure decreased spleen cell (SC) response to T cell mitogen concanavalin A (Con A). 3H-TdR [deoxythymidine] incorporation of SC from O2 exposed mice (O2 SC) compared to those of control mice (Air SC) decreased significantly after 72 and 87 h O2 exposure. The dose response kinetics to Con A were identical in O2 SC or Air SC. Increasing SC number did not restore the response to Con A and the depressed hyperoxic effect was not related to suppressor cells in the spleen of O2 exposed mice. Response of O2 SC to Con A was restored by the thiol compound 2-mercaptoethanol (2-ME), and the degree of restoration by 2-ME, was inversely proportional to the depressed response. Addition of intact peritoneal cells (PC) induced restoration within the same range as 2-ME. Restoration of the mitogenic response by 2-ME involved antioxidant properties and suggested that macrophages were functionally injured by O2 exposure. In cases where mitogen response was highly depressed, restoration was only partial; in these conditions in vivo O2 injury probably involved both macrophages and splenic T cells. The mechanisms of O2 toxicity were discussed in terms of free radical generation under hyperoxic conditions.