AVP and Hypernatremia: PrRP is involved in various functions challenged by hypernatremia, like the cardiovascular regulation (Yamada et al. 2009) and the control of oxytocin (promotes sodium excretion) and vasopressin (AVP, stimulates water retention) release from the magnocellular cells of the SON and PVN (Maruyama et al. 1999; Uchida et al. 2010).