Spectrophotometric oxyhemoglobin

Spectrophotometric Oxyhemoglobin Method Bauld, W. S., and Greenway, R. M., Chemical Determinadon of Estrogens 30 227... 

Spectrophotometric Oxyhemoglobin Method, Measurement of Oxygen Consumption... 

B rzu, Octavian, Measurement of Oxygen Consumption by the Spectrophotometric Oxyhemoglobin Method. ... 

The spectrophotometric methods make use of either the different absorption spectra of MHb and Hb, or of the decrease of NADPH2 absorbance at 340 or 366 mp. MHb has an absorption peak at 630 mp while oxyhemoglobin at 576 m x. By this, the absorbance of oxyhemoglobin appearing or the decrease at 630 mp may be a measure for MHbR activity (H23). 

The problem of whether ozone itself reaches and reacts with the blood was studied. Earlier in vitro studies had shown that ozone does not oxidize the ferrous ion of oxyhemoglobin to the ferric ion to produce methomoglobin when 39.6 p.p.m. is bubbled at a rate of 150 ml. per minute directly into whole blood. Ozonized plasma, on the other hand, showed a definite increase in absorbance at 250, 280, and 350 m/jL (Table V). Consequently, blood plasma from 27 young rats exposed to 2.4 p.p.m. of ozone for 3 hours per day, 5 days per week for 8 weeks, and two animals exposed to an acute dose of 40 p.p.m. of ozone for 3 hours and 20 minutes was examined spectrophotometrically. The absorbances obtained did not differ significantly from those obtained for plasma for 30 control animals. 

Nl. Nahas, G. G., Spectrophotometric determination of hemoglobin and oxyhemoglobin in whole hemolyzed blood. Science 113, 723 (1951). 

Globin was prepared from crystalline bovine oxyhemoglobin by the method originally developed for Palemyssarda by Rossi Fanelli, Anto-nini, and Caputo (28) with our adaptation (20). The globin content was determined spectrophotometrically at 280 m/x with = 8.5. A sample of polyhistidine was obtained from the Biophysics Department, Weiz-mann Institute of Science. All other chemicals were purchased from commercial sources. 

The state of ionization of the imidazole residue linked to hemoglobin iron has no hitherto observed influence on the light absorption of hemi-, hemo-, or oxyhemoglobin. It seems possible, however, that very careful spectrophotometric determinations might reveal slight differences corresponding to the pK values of the heme-linked imidazole groups. 

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