Fig. 3.  a–c , Plots of cumulative urinary output  versus time in sheep after infusion of 25 ml/kg 0.9% saline in 20 min (infusion only), bleeding of 300 ml in 5 min (hemorrhage only), and the combination of both, with bleeding immediately preceding the infusion (hemorrhage plus infusion).  d–f , Plots of fractional changes from the baseline volume of the central compartment (  V ^C0 ), obtained from changes in hemoglobin concentrations  versus time for the corresponding experimental sessions.