High concentrations of oxygen modulate in vitro Con A responses of rat lymphoid cells. Effect of 2-mercaptoethanol

The effects of different normobaric oxygen concentrations (40, 60 and 95%) on the survival and the proliferative response to Con A of rat lymphoid cells were studied. Spleen, thymus and peripheral blood mononuclear cells were tested. We found that oxygen concentrations modulated the proliferative response independently of cell survival. The addition of 2-mercaptoethanol (2-ME) partially prevented the toxic effects of hyperoxia but the population of thymocytes which responded to Con A stimulation appeared to be less sensitive to the protective action of 2-ME. The relationship between oxygen concentrations and the lymphoid proliferative response could be used as a model of oxidant immunodepression for evaluating pharmacological effects of antioxidant compounds.