D-factor and growth hormone enhance tumor necrosis factor-induced increase of Mn superoxide dismutase mRNA and oxygen tolerance.

D-Factor (differentiation-inducing factor or leukemia inhibitory factor) and growth hormone are proteins that regulate growth and differentiation of cells. In this study, we demonstrated that recombinant human D-factor and growth hormone caused a slight but significant protection of adult rats against oxygen toxicity without affecting levels of pulmonary manganous superoxide dismutase (MnSOD) mRNA. D-Factor and growth hormone also markedly enhanced tumor necrosis factor (TNF)-induced oxygen tolerance. This latter effect was associated with a marked enhancement of TNF-mediated induction of pulmonary MnSOD mRNA.