Effects of Stroma Free Hemoglobin on Blood Pressure and Renal Function in the Hypotensive Rat: Potential Role of Nitric Oxide Inactivation by Hemoglobin

Abstract

The short term systemic and renal hemodynamic effects of two stroma free hemoglobin (SFH) solutions, one unmodified and the other modified by cross-linking, were examined in anesthetized rats following hemorrhagic hypotension. Both forms of SFH increased MAP and GFR to baseline, pre-hemorrhage values. The increase in MAP induced by unmodified SFH (from 61 +/- to 111 +/- 7 mmHg) was greater than the increase in MAP caused by an albumin solution iso-oncotic to the unmodified SFH solution (63 +/- 3 to 82 +/-2 mmHg) (p < 0.05). Similarly, the increase in MAP associated with modified SFH infusion (56 +/- 4 to 96 +/- 5 mmHg) was also substantially greater than that induced by an albumin solution of comparable oncotic pressure to the modified SFH (59 +/- 4 to 71 +/- 5 mmHg) (p < 0.05). GFR increased in response to the unmodified SFH from 1.1 +/- 0.5 to 2.7 +/- 0.3 ml/min (p < 0.05), while the modified SFH increased GFR from 0.7 +/- 0.2 to 2.7 +/- 0.3 ml/min (p < 0.05). As with MAP, the increase in GFR induced by both SFH solutions was greater than that associated with the oncotically matched albumin solutions (p <0.05). In separate experiments, the effects of nitric oxide (NO) inhibition with L-NAME on MAP following hemorrhagic hypotension and subsequent infusion of unmodified SFH or albumin was also examined. In the albumin infused rats, L-NAME increased MAP from 82 +/- 4 to 104 +/- 7 mmHg (p < 0.05). In marked contrast, NO inhibition with L-NAME had no further effect on MAP when infused after SFH (119 +/- 3 to 112 +/- 3, p = NS). We conclude that both unmodified and modified SFH solutions acutely improve MAP and GFR by the combined effects of intravascular volume expansion resulting from the colloid effect of the protein and by inactivation of NO.

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Document Details

Document Type
Technical Report
Publication Date
Apr 13, 1994
Accession Number
ADA360319

Entities

People

  • Alex Thompson
  • Amy E. Mcgarry
  • C. R. Valeri
  • Wilfred Lieberthal

Organizations

  • Boston University

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  • Biomedical

DTIC Thesaurus Topics

  • Arteries
  • Availability
  • Blood
  • Blood Substitutes
  • Body Temperature
  • Cardiovascular Diseases
  • Cardiovascular Physiological Phenomena
  • Cardiovascular System
  • Catheters
  • Filtration
  • Hemorrhage
  • Inhibition
  • Measurement
  • Molecules
  • Navy
  • Side Effects
  • United States

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