The Effect of Methemoglobin Formation in Sickle Cell Disease*

Beutler, Ernest

doi:10.1172/jci104410

Cited by 71 publications

(22 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the latter, a small amount of red cell suspension was anaerobically transferred into 10% formaldehyde in saline for fixation. 400 cells were then counted using previously described criteria (12). The This result is in agreement with data obtained by others (2).…”

Section: Methodssupporting

confidence: 88%

Effects of Cyanate and 2,3-Diphosphoglycerate on Sickling RELATIONSHIP TO OXYGENATION

Jensen¹,

Bunn²,

Halikas³

et al. 1973

J. Clin. Invest.

View full text Add to dashboard Cite

Section: Methodssupporting

confidence: 88%

Effects of Cyanate and 2,3-Diphosphoglycerate on Sickling RELATIONSHIP TO OXYGENATION

Jensen¹,

Bunn²,

Halikas³

et al. 1973

J. Clin. Invest.

View full text Add to dashboard Cite

“…1 B), than an oxygen-based HbS modifier like potassium cyanate. Another possibility is that NO increases erythrocyte Mhb levels, thereby altering oxygen affinity (20)(21)(22). However, since our in vitro and in vivo studies recorded only very low levels of Mhb in both AA and SS RBCs, it is unlikely that Mhb contributed to the selective increase in HbS RBC oxygen affinity.…”

Section: Discussionmentioning

confidence: 77%

Low concentrations of nitric oxide increase oxygen affinity of sickle erythrocytes in vitro and in vivo.

Head¹,

et al. 1997

View full text Add to dashboard Cite

The hallmark of sickle cell disease (SCD) is the polymerization of deoxygenated sickle hemoglobin (HbS). In SCD patients, one strategy to reduce red blood cell (RBC) sickling is to increase HbS oxygen affinity. Our objective was to determine if low concentrations of nitric oxide (NO) gas would augment the oxygen affinity of RBCs containing homozygous HbS (SS). Blood containing normal adult hemoglobin (AA) or SS RBCs was incubated in vitro in the presence of varying concentrations of NO up to 80 ppm, and oxygen dissociation curves (ODCs) were measured. In addition, blood was obtained from three AA and nine SS volunteers, before and after breathing 80 ppm NO in air for 45 min, and the ODCs were measured. Exposure of SS RBCs to 80 ppm NO in vitro for 5 min or longer decreased the partial pressure of oxygen at which hemoglobin is 50% saturated with oxygen (P 50 ), an average of 15% (4.8 Ϯ 1.7 mmHg mean Ϯ SE; P Ͻ 0.001). The increase in SS RBC oxygen affinity correlated with the NO concentration. The P 50 of AA RBCs was unchanged ( P Ͼ 0.1) by 80 ppm NO. In SS volunteers breathing 80 ppm NO for 45 min, the P 50 decreased ( P Ͻ 0.001) by 4.6 Ϯ 2.0 mmHg. 60 min after NO breathing was discontinued, the RBC P 50 remained decreased in five of seven volunteers in whom the ODC was measured. There was no RBC P 50 change ( P Ͼ 0.1) in AA volunteers breathing NO. Methemoglobin (Mhb) remained low in all subjects breathing NO (SS Mhb 1.4 Ϯ 0.5%), and there was no correlation ( r ϭ 0.02) between the reduction in P 50 and the change in Mhb. Thus, low concentrations of NO augment the oxygen affinity of sickle erythrocytes in vitro and in vivo without significant Mhb production. These results suggest that low concentrations of NO gas may offer an attractive new therapeutic model for the treatment of SCD. ( J. Clin. Invest. 1997. 100: 1193-1198.)

show abstract

“…The entire suspension was then incubated for 10 (v/v) formaldehyde in saline for fixation. Five hundred cells were counted by described criteria (6). The viscosity of dimethyl adipimidate-treated and control cells was measured in a Wells Brookfield cone plate microviscomneter model LVT, adapted to maintain controlled atmospheric gas tension (7).…”

Section: Methodsmentioning

confidence: 99%

Dimethyl adipimidate: a new antisickling agent.

Lubin¹,

Peña²,

Mentzer³

et al. 1975

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

A new approach to the prevention of sickling in vitro by use of the bifunctional crosslinking reagent, dimethyl adipimidate, is described. Prior treatment of sickle erythrocytes with dimethyl adipimidate will inhibit sickling in completely deoxygenated erythrocytes. Treated erythrocytes do not demonstrate the potassium loss and viscosity increase that usually accompany sickling. The oxygen affinity of hemoglobin in these cells is increased independently from changes in the concentration of 2,3-diphosplioglycerate. The (v/v) formaldehyde in saline for fixation. Five hundred cells were counted by described criteria (6). The viscosity of dimethyl adipimidate-treated and control cells was measured in a Wells Brookfield cone plate microviscomneter model LVT, adapted to maintain controlled atmospheric gas tension (7). After adjustment of the hematocrit to 40 i 1%, the blood was equilibrated for 1 hr with humidified 95% N2 and 5% CO2 in an IL tonometer model no. 237, then transferred in a closed system to the viscometer. The viscosity was measured at shear rates ranging from 4.5 to 90 sec' during continued exposure to nitrogen.Studies in vitro of erythrocyte metabolism and of net K + loss were conducted by incubation at 370 of thrice-washed erythrocytes in Krebs Henseleit buffer with added glucose (10 mM) in the presence of 0.1 mM ouabain. The samples were continuously equilibrated with moistened gas mixtures consisting of nitrogen plus 20%, 3.3%, or 0% oxygen, and pH was maintained at 7.45 4i 0.05 by varying the CO2 concentration with a gasometric pH stat (8). Supernatant K+ concentration was determined by flame photometry. 2,3-Diphosphoglycerate (9) concentrations in erythrocytes were determined in perchloric acid extracts.The oxygen affinity of whole blood, expressed as p50 (that oxygen tension at which hemoglobin is half-saturated), was determined by measurement of hemoglobin oxygen saturation and P02 after equilibration of the samples with gas mixtures containing 2.2%, 2.8%, 3.2%, and 3.9% oxygen plus 5% CO2 and the remainder nitrogen. The p50 was calculated by a best fit analysis of these data and corrected to a pH of 7.4 (10).Hemolysates and globin were prepared by standard methods. Gel filtration in Sephadex G-100 was performed by the method of Andrews (11). The column was calibrated with aldolase (molecular weight 158,000), ovalbumin (molecular weight 45,000), and chymotrypsinogen A (molecular weight 25,000). Hemoglobin electrophoresis was performed on cellulose acetate strips at pH 8.65 in a Beckman microphor system. Barbital buffer, 25 mMI, pH 8.0, was used for electrophoretic separation of globin chains and the cellulose acetate strips were soaked in the same buffer with 8 M urea and 5 mM 2-mercaptoethanol. Spectra were recorded with a Cary 14 recording spectrophotometer.

show abstract

The Effect of Methemoglobin Formation in Sickle Cell Disease*

Cited by 71 publications

References 24 publications

Effects of Cyanate and 2,3-Diphosphoglycerate on Sickling RELATIONSHIP TO OXYGENATION

Effects of Cyanate and 2,3-Diphosphoglycerate on Sickling RELATIONSHIP TO OXYGENATION

Low concentrations of nitric oxide increase oxygen affinity of sickle erythrocytes in vitro and in vivo.

Dimethyl adipimidate: a new antisickling agent.

Contact Info

Product

Resources

About