This microcirculatory study compared the effects on oxygen transport of two hemodilution fluids: HBOC-201 (Biopure Corp., Cambridge, MA) a Hemoglobin-Based Oxygen Carrier (HBOC), and 5.9% Human Serum Albumin (HSA) an iso-oncotic non-oxygen carrying colloid solution. Measurements using intravital microscopy were made on the spinotrapezius muscle of male, Sprague-Dawley rats. Interstitial PO2 was measured using phosphorescence quenching microscopy, and recorded before and after isovolemic hemodilutions (HD) at hematocrits of 40% (baseline), 30% (moderate HD) and 15% (severe HD). Oxygen consumption (VO2) of the spinotrapezius muscle was derived from PO2 recordings following the rapid inflation of a plastic bag placed around the objective. When the bag was inflated, blood flow in the muscle was arrested and PO2 rapidly fell over several seconds; the rate of decline of PO2 was proportional to VO2. For moderate HD (Hct ~ 30%) with HBOC-201, interstitial PO2 did not change from baseline conditions (Hct ~ 40%), while HD with HSA showed a decrease. For severe HD (Hct ~ 15%) both PO2 and VO2 were significantly lower for the HSA group than for the HBOC-201 group. These findings indicate that HBOC-201 maintains both a higher PO2 and VO2 during hemodiluted states compared with a non-oxygen carrying colloid solution (HSA). Furthermore, 5.9% HSA does not affect the mean arterial pressure (MAP) and vessel diameters, whereas HBOC-201 causes vasoconstriction, and consequently an increase in MAP. However, the vasoconstriction is not uniform among different branches of the arteriolar network, and most of the changes occur in the larger vessels, i.e., feed and arcade arterioles, while minimal in smaller vessels, i.e., transverse arterioles. In addition, findings show that MAP and vessel diameters return to baseline within 1-3 hours, implying that vasoconstriction and hypertension caused by HBOC-201 are acute responses.
| Identifer | oai:union.ndltd.org:vcu.edu/oai:scholarscompass.vcu.edu:etd_retro-1032 |
| Date | 01 January 2007 |
| Creators | Song, Bjorn Kyungsuck |
| Publisher | VCU Scholars Compass |
| Source Sets | Virginia Commonwealth University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Retrospective ETD Collection |
| Rights | © The Author |
Page generated in 0.0019 seconds