NPPA and Polyuria: Also consistent with past findings in T9 contused rats was a decrease in serum AVP and an increase in urinary ANP after chronic T3 SCI.8,9 Both ANP and AVP are crucial for body water/solute homeostasis, and the change of their alteration observed in this and recent studies are in the direction that would result in polyuria.9,36 The similar findings with T3 SCI animals in relation to T9 SCI animals previously reported9,14 suggest that these mechanisms are present regardless of level of injury.