Hemoglobin effect

Awasthi VD, Garcia D, Klipper R, et al. Neutral and anionic liposome-encapsulated hemoglobin effect of postinserted poly(ethylene glycol)-distearoylphospha-tidylethanolamine on distribution and circulation kinetics. J Pharmacol Exp Ther 2004 309 241. 

It is well known that hemoglobin effectively absorbs molecular oxygen in the lungs and desorbs it in the terminal tissue although there is only a small difference in the partial pressure of oxygen. This phenomenon is clearly demonstrated by Fig. 23. 

VonDobschuetz, E. Hoffmann, T. Messmer, K. Diaspirin cross-linked hemoglobin effectively restores pancreatic microcirculatory failure in hemorrhagic shock. Anesthe-siol. 1999, 91, 1754-1762. 

A6. Aleyassine, H., Gardiner, R., Blankstein, L. A., and Dempsey, M. E., Agar gel electrophoretic determination of glycosylated hemoglobin Effect of variant hemoglobins, hyperlipidemia, and temperature. Clin. Chem. 27, 472-475 (1981). 

Absorption route Can enter the body by halation or ingestion. Harmful atmospheric concentrations can buid up fairly rapidy on evaporation at >prox. 2(7 C - even more rapidly in aerosol form. knmedMe ellecis Irritotes the eyes, skin and respiratory tract. Liquid destroys the skin s natural oils. cause formation of carboj hemoglobin. Effects of protengod/repoalodmqtoeMro Can affect the blood. Can dam the liver. In serious cases risk of unconsciousness. ... 

Pinna MC, Salts A, Monduzzi M, Ninham BW (2005) Hofmeister series the hydrolytic activity of Aspergillus niger lipase depends on specific anion effects. J Phys Chem B 109 5406-5408 PoUlon WN, Betties JF (1979) Deoxygenated sickle hemoglobin. Effects of lyotropic salts on its solubility. J Bio Chem 254 3462-3467... 

Fig. 8. Hemoglobin. Effect of pH on the o gen saturation curve of hemoglobin. As acidity increases, i. e. a decrease in pH from 7.6 to 7.2, oxygen release is favored (arrow) because percentage saturation is less at any give oxygen partial pressure.

Flg.9. Hemoglobin. Effect of 2,3-diphosphoglyce-rate on the oxygen saturation curve of hemoglobin. 

Moffat, K. Gelation of sickle cell hemoglobin Effects of hybrid tetramer formation in hemoglobin mixtures. Science 185, 274-277 (1974)... 

The allosteric effect is seen in hemoglobin which can exist in two quaternary stmctural states oxygenated (R) or deoxygenated (T). The binding of one O2 or some other effector to one of the subunits stabilizes the R form as compared to the T form. Binding of a second and third O2 stabilizes it even further. 

After these reports there were many attempts to administer hemoglobin solutions to humans. Many of these patients did well, but others demonstrated hypertension, bradycardia, oliguria, and even anaphylaxis. These untoward effects were not correlated with specific biochemical properties of the solutions themselves. 

The transition between the T and R states of hemoglobin is also deeply involved in the Bohr effect and cooperativity. Therefore stabilization of either of the two stmctures should diminish these effects, which have important physiologic consequences. The clinical consequences of stabilization are not known. 

In 1982 a study of the usefulness of DBBF in the production of a blood substitute was reported (99). A single modification achieved the dual goals of reduced oxygen affinity and restricted tetramer—dimer dissociation. This work was confirmed in 1987 (98). The product, called aa-hemoglobin, was formulated in Ringer s lactate. P q under physiologic conditions is 3.7 kPa (28.0 torr). Hill s parameter is 2.2, and the Bohr effect was reduced (100). Plasma retention was increased, and the product appeared to be less heterogeneous than some of the other derivatives under study. Its production was scaled up by Baxter Healthcare Corp., under contract to the U.S. Army. 

---