Transferrin treatment corrects aging-related immunologic and hormonal decay in old mice

Experiments were conducted to study the effect of heterologous plasma trans ferrins separated and purified from human plasma pools on endocrine and imm une functions of old, aging mice. Two similar experiments have shown that p arenteral treatment with iron and zinc-free human transferrins produces a s ignificant improvement of immunological and endocrine functions in the agin g mice toward more juvenile values. Those changes occur in the thymus and i ts cell subsets, in peripheral blood lymphocytes, in the restoration of juv enile levels of thyroxine, in the increase of testis weight, and in the nor malization of plasma zinc levels. These totally unsuspected effects of tran sferrin in aging mice suggest a most important role of endogenous transferr ins in the maintenance of neuroendocrine and immune functions. The mechanis m remains unexplained although the basic immunoenhancing and anti-apoptotic effect of transferrin-vehiculated zinc may be relevant. (C) 2000 Elsevier Science Inc. All rights reserved.