BACKGROUND: We have shown previously that hemorrhagic @entity551 is associated with a progressive development of vascular hyporeactivity to @entity1063 (NE). The present study investigated whether select crystalloid or colloid resuscitation fluids would ameliorate this effect. METHOD: Anesthetized male @entity35 were hemorrhaged to and maintained at a mean arterial pressure (MAP) of 50 mm Hg for 60 minutes. @entity35 (n = 7 per group) were then resuscitated with lactated Ringer's (LR), 7.5% hypertonic saline (HS) for 1 hour followed by LR (HS-LR), Hespan, or Hextend to restore and maintain MAP to 70 mm Hg over 4 hours. Additional hemorrhaged groups were resuscitated with LR to the baseline MAP (LR-BL) or received no resuscitation. A sham @entity548 group served as controls. The responses of MAP and the blood flow of the superior mesenteric, celiac, left renal, and left femoral arteries to NE (3 microg/kg administered intravenously) were measured at BL (prehemorrhage); at the end of the @entity551 period; and at 1, 2, and 4 hours after resuscitation. RESULTS: @entity551 significantly (p < 0.01) reduced the NE-induced pressor response in MAP and significantly reduced the contractile responses (reflected by the @entity551 after NE administration) of the four arteries to NE. Hespan and Hextend infusion improved the NE response of MAP and the contractile responses of the observed arteries to NE significantly better than LR, HS-LR, or LR-BL. The colloids improved the vascular contractile responses to NE in the superior mesenteric and left femoral arteries and the pressor response of MAP to NE, to 80% to 90% of their basal response level compared with 40% to 60% with the crystalloid fluids (p < 0.05). LR-BL infusion resulted in hemodilution, with no added benefit to vascular responsiveness. CONCLUSION: These data suggest that @entity551 resuscitation to 70 mm Hg with colloids was better than crystalloids in improving vascular responsiveness to the pressor effects of NE and required smaller volumes. Normotensive resuscitation with LR was not better than @entity551 resuscitation. Not all vasculatures improved equally after fluid resuscitation.

Effects of crystalloid and colloid resuscitation on @entity548 -induced vascular hyporesponsiveness to @entity1063 in the XXXX .

@entity35 :: ('10116', 'Species') :: ['Rats', 'rats'] @entity1063 :: ('MESH:D009638', 'Chemical') :: ['norepinephrine'] @entity551 :: ('MESH:D007022', 'Disease') :: ['reduction of blood flow', 'Hemorrhagic hypotension', 'hypotensive', 'hypotension'] @entity548 :: ('MESH:D006470', 'Disease') :: ['hemorrhage']
@entity35 :: (10116,Species) :: ['rat']
