Modulation of Oxygen Affinity in Hemoglobin-based Oxygen Carriers

Migita, Russell, Armando Gonzales, Maria L. Gonzales, Kim D. Vandegriff, and Robert M. Winslow. Blood volume and cardiac index in rats after exchange transfusion with hemoglobin-based oxygen carriers. J. Appl. Physiol. 82(6): 1995–2002, 1997.—We have measured plasma volume and cardiac index in rats after 50% isovolemic exchange transfusion with human hemoglobin cross-linked between the α-chains with bis(3,5-dibromosalicyl)fumarate (ααHb) and with bovine hemoglobin modified with polyethylene glycol (PEGHb). ααHb and PEGHb differ in colloid osmotic pressure (23.4 and 118.0 Torr, respectively), oxygen affinity (oxygen half-saturation pressure of hemoglobin = 30.0 and 10.2 Torr, respectively), viscosity (1.00 and 3.39 cP, respectively), and molecular weight (64,400 and 105,000, respectively). Plasma volume was measured by Evans blue dye dilution modified for interference by plasma hemoglobin. Blood volumes in PEGHb-treated animals were significantly elevated (74.0 ± 3.5 ml/kg) compared with animals treated with ααHb (49.0 ± 1.2 ml/kg) or Ringer lactate (48.0 ± 2.0 ml/kg) or with controls (58.2 ± 1.9 ml/kg). Heart rate reduction after ααHb exchange is opposite to that expected with blood volume contraction, suggesting that ααHb may have a direct myocardial depressant action. The apparently slow elimination of PEGHb during the 2 h after its injection is a consequence of plasma volume expansion: when absolute hemoglobin (concentration × plasma volume) is compared for PEGHb and ααHb, no difference in their elimination rates is found. These studies emphasize the need to understand blood volume regulation when the effects of cell-free hemoglobin on hemodynamic measurements are evaluated.

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Fabrication and evaluation of hemoglobin-based polydopamine microcapsules as oxygen carriers

Chemical Communications ◽

10.1039/c8cc00095f ◽

2018 ◽

Vol 54 (33) ◽

pp. 4136-4139 ◽

Cited By ~ 7

Author(s):

Chunmei Yu ◽

Xin Huang ◽

Dongping Qian ◽

Fengfeng Han ◽

Linyi Xu ◽

...

Keyword(s):

Oxygen Affinity ◽

High Oxygen ◽

Electrochemical Methods ◽

Oxygen Carriers ◽

High Oxygen Affinity

Polydopamine-hemoglobin (PDA-Hb) microcapsules possess a high oxygen affinity and could bind and release oxygen reversibly as demonstrated by electrochemical methods.

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Sodium nitrite therapy attenuates the hypertensive effects of HBOC-201 via nitrite reduction1

Biochemical Journal ◽

10.1042/bj20090735 ◽

2009 ◽

Vol 422 (3) ◽

pp. 423-432 ◽

Cited By ~ 25

Author(s):

Cilina Rodriguez ◽

Dario A. Vitturi ◽

Jin He ◽

Marianne Vandromme ◽

Angela Brandon ◽

...

Keyword(s):

Mild Hypertension ◽

Oxygen Affinity ◽

Nitrite Reduction ◽

Oxygen Carriers ◽

Low Oxygen ◽

Functional Importance ◽

No Donor ◽

Ringer’S Solution ◽

Lactated Ringer's Solution ◽

Low Oxygen Affinity

Hypertension secondary to scavenging of NO remains a limitation in the use of HBOCs (haemoglobin-based oxygen carriers). Recent studies suggest that nitrite reduction to NO by deoxyhaemoglobin supports NO signalling. In the present study we tested whether nitrite would attenuate HBOC-mediated hypertension using HBOC-201 (Biopure), a bovine cross-linked, low-oxygen-affinity haemoglobin. In a similar way to unmodified haemoglobin, deoxygenated HBOC-201 reduced nitrite to NO with rates directly proportional to the extent of deoxygenation. The functional importance of HBOC-201-dependent nitrite reduction was demonstrated using isolated aortic rings and a murine model of trauma, haemorrhage and resuscitation. In the former, HBOC-201 inhibited NO-donor and nitrite-dependent vasodilation when oxygenated. However, deoxygenated HBOC-201 failed to affect nitrite-dependent vasodilation but still inhibited NO-donor dependent vasodilation, consistent with a model in which nitrite-reduction by deoxyHBOC-201 counters NO scavenging. Finally, resuscitation using HBOC-201, after trauma and haemorrhage, resulted in mild hypertension (~5–10 mmHg). Administration of a single bolus nitrite (30–100 nmol) at the onset of HBOC-201 resuscitation prevented hypertension. Nitrite had no effect on mean arterial pressure during resuscitation with LR (lactated Ringer's solution), suggesting a role for nitrite–HBOC reactions in attenuating HBOC-mediated hypertension. Taken together these data support the concept that nitrite can be used as an adjunct therapy to prevent HBOC-dependent hypertension.

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Hemoglobin vesicles improve wound healing and tissue survival in critically ischemic skin in mice

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00430.2009 ◽

2009 ◽

Vol 297 (3) ◽

pp. H905-H910 ◽

Cited By ~ 20

Author(s):

Jan A. Plock ◽

Nassim Rafatmehr ◽

Dubravko Sinovcic ◽

Jonas Schnider ◽

Hiromi Sakai ◽

...

Keyword(s):

Nitric Oxide ◽

Wound Healing ◽

Nitric Oxide Synthase ◽

Endothelial Nitric Oxide Synthase ◽

Trauma Surgery ◽

Oxygen Affinity ◽

Oxygen Carriers ◽

Total Blood ◽

Oxide Synthase ◽

Endothelial Nitric Oxide

Local hypoxia, as due to trauma, surgery, or arterial occlusive disease, may severely jeopardize the survival of the affected tissue and its wound-healing capacity. Initially developed to replace blood transfusions, artificial oxygen carriers have emerged as oxygen therapeutics in such conditions. The aim of this study was to target primary wound healing and survival in critically ischemic skin by the systemic application of left-shifted liposomal hemoglobin vesicles (HbVs). This was tested in bilateral, cranially based dorsal skin flaps in mice treated with a HbV solution with an oxygen affinity that was increased to a P50 (partial oxygen tension at which the hemoglobin becomes 50% saturated with oxygen) of 9 mmHg. Twenty percent of the total blood volume of the HbV solution was injected immediately and 24 h after surgery. On the first postoperative day, oxygen saturation in the critically ischemic middle flap portions was increased from 23% (untreated control) to 39% in the HbV-treated animals ( P < 0.05). Six days postoperatively, flap tissue survival was increased from 33% (control) to 57% ( P < 0.01) and primary healing of the ischemic wound margins from 6.6 to 12.7 mm ( P < 0.05) after HbV injection. In addition, higher capillary counts and endothelial nitric oxide synthase expression (both P < 0.01) were found in the immunostained flap tissue. We conclude that left-shifted HbVs may ameliorate the survival and primary wound healing in critically ischemic skin, possibly mediated by endothelial nitric oxide synthase-induced neovascularization.

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Alkaline Dissociation Products of Lumbricus Terrestris Hemoglobin Viewed with the STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098678 ◽

1981 ◽

Vol 39 ◽

pp. 434-435

Author(s):

O. H. Kapp ◽

M. Ohtsuki ◽

N. Robin ◽

S. N. Vinogradov ◽

A. V. Crewe

Keyword(s):

Carbon Film ◽

Lumbricus Terrestris ◽

Uranyl Acetate ◽

Acetate Solution ◽

Oxygen Carriers ◽

Complex Molecules ◽

Thin Carbon ◽

Thin Carbon Film ◽

Multiple Copies ◽

Hill Coefficients

Annelid extracellular hemoglobins are among the largest known proteins (M.W = 3.9 x 106), and together with the hemocyanins are the largest known oxygen carriers. They display oxygen affinities generally higher than those o vertebrate hemoglobins with Hill coefficients ranging from slightly higher than unity to values as high as 5-6. These complex molecules are composed of multiple copies of as many as six different polypeptides and posse: approximately 150 hemes per molecule.The samples were diluted to 100-200 μg/ml with distilled water just before application to a thin carbon film (∽15 Å thick). One percent (w/v) uranyl acetate solution was used for negative staining for 2 minutes and dried in air. The specimens were examined with the high resolution STEM. Their general appearance is that of a hexagonal bilayer (Fig. 1), each layer consisting of six spheroidal subunits. The corner to corner hexagonal dimensic is approximately 300 Å and the bilayer thickness approximately 200 Å.

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The biochemistry of drugs and doping methods used to enhance aerobic sport performance

Essays in Biochemistry ◽

10.1042/bse0440063 ◽

2008 ◽

Vol 44 ◽

pp. 63-84 ◽

Cited By ~ 7

Author(s):

Chris E. Cooper

Keyword(s):

Oxygen Uptake ◽

Oxygen Content ◽

Oxygen Delivery ◽

Sport Performance ◽

Blood Substitutes ◽

Altitude Training ◽

Blood Oxygen ◽

Oxygen Carriers ◽

Sports Performance ◽

Blood Doping

Optimum performance in aerobic sports performance requires an efficient delivery to, and consumption of, oxygen by the exercising muscle. It is probable that maximal oxygen uptake in the athlete is multifactorial, being shared between cardiac output, blood oxygen content, muscle blood flow, oxygen diffusion from the blood to the cell and mitochondrial content. Of these, raising the blood oxygen content by raising the haematocrit is the simplest acute method to increase oxygen delivery and improve sport performance. Legal means of raising haematocrit include altitude training and hypoxic tents. Illegal means include blood doping and the administration of EPO (erythropoietin). The ability to make EPO by genetic means has resulted in an increase in its availability and use, although it is probable that recent testing methods may have had some impact. Less widely used illegal methods include the use of artificial blood oxygen carriers (the so-called ‘blood substitutes’). In principle these molecules could enhance aerobic sports performance; however, they would be readily detectable in urine and blood tests. An alternative to increasing the blood oxygen content is to increase the amount of oxygen that haemoglobin can deliver. It is possible to do this by using compounds that right-shift the haemoglobin dissociation curve (e.g. RSR13). There is a compromise between improving oxygen delivery at the muscle and losing oxygen uptake at the lung and it is unclear whether these reagents would enhance the performance of elite athletes. However, given the proven success of blood doping and EPO, attempts to manipulate these pathways are likely to lead to an ongoing battle between the athlete and the drug testers.

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