CILIARY NEUROTROPHIC FACTOR (CNTF) INDUCES SERUM AMYLOID-A, HYPOGLYCEMIA AND ANOREXIA, AND POTENTIATES IL-1 INDUCED CORTICOSTERONE AND IL-6 PRODUCTION IN MICE

Ciliary neurotrophic factor (CNTF) supports the survival of ciliary ganglion neurons and was shown to induce the synthesis of acute-phase proteins and fever, We studied the effect of CNTF, alone or in association with IL-1, on levels of corticosterone (CS), glucose, serum amyloid A (SAA), and IL-6, We also compared the effect of CNTF with that of IL-6, since the gp130 receptor subunit for CNTF is shared with that of IL-6, A single intravenous injection of CNTF induced hypoglycaemia and SAA and potentiated IL-1-induced CS and IL-6, Chronic CNTF, but not IL-6, resulted in decreased food intake and body weight up to days 6-7, After this time, body weight and food intake recovered even if CNTF treatment was continued, indicating that a phenomenon of tolerance occurred, Finally, CNTF (unlike IL-1) was not toxic in adrenalectomized mice, Therefore the similarities of CNTF activities with those of other cytokines, particularly IL-6, might go beyond the activation of the same receptor-signal transduction pathway of IL-6.