Cellular bioenergetics changes in magnocellular neurons may affect copeptin expression in the late phase of sepsis

•Copeptin plays an important role in the correct structural formation of vasopressin.•Increased hypothalamic IL-1β and NO levels cause bioenergetics changes.•Apoptosis markers increased in magnocellular neurons during sepsis.•Decreased copeptin expression compromising AVP synthesis and secretion in the sepsis.

We investigated whether inflammatory mediators during cecal ligation and puncture (CLP)-induced sepsis may diminish copeptin expression in magnocellular neurons, thus affecting arginine-vasopressin (AVP) synthesis. The transcript abundance of IL-1β, IL-1R1, iNOS and HIF-1α was continuously elevated. IL-1β, iNOS and cytochrome c protein levels progressively increased until 24 h. Immunostaining for these proteins was higher at 6 and 24 h, as also seen in the annexin-V assay, while copeptin was continuously decreased. This suggests that increased IL-1β and NO levels may cause significant bioenergetics changes in magnocellular neurons, affecting copeptin expression and compromising AVP synthesis and secretion in the late phase of sepsis.