Abstracts Abnormal Blood Pigments

ABNORMAL BLOOD PIGMENTS CLEMENT A. FINCH, M.D. , AND JOSEPH F. ROSS, M.D. THE BLOOD PIGMENTS; THE PROPERTIES AND QUANTITATIVE DETERMINATION WITH SPECIAL REFERENCE TO THE SPECTROPHOTOMETRIC METHODS. H. 0. Michel andJ. S. Harris. J. Lab. & Clin. Med., a;.445-463, 1940. The authors present an orientational discussion of the nature and chemical properties of the various blood pigments derived from hemoglobin. The absorption spectra of these substances and their reactions to certain chemicals are described. Particularly useful is their outline of the qualitative identification by simple spectroscopy of methemoglobin, sulfhemoglobin, hematin, and pseudomethemoglobin (methemalbumin). Quantitative methods of analysis, i.e., gasometrie, combined gasometric and colorimetrie, and spcctrophotometric are reviewed. The authors present a speetrophotometrie method with experimental data based on extinction coefficients for the determination of mixtures of sulfhemoglobin, methemoglobin, and oxyhemoglobin. C. A. F. A RAPID SPEcTR0PH0T0METRIc METHOD FOR THE DETERMINATION OF METHEMOGLOBIN AND CARBONYLHEMOGLOBIN IN BLOOD. B. L. Herecker and F. S. Brackett. J. Biol. Chem. , 152. 66 -677, 1944. This method utilizes the same principle as the method employed by Evelyn and Malloy (J. Biol. Chem. 126. 1938). The instruments used were the Coleman speetrophotometer and especially constructed photometers. Measurements were made at 8ooo A and at 4965 A. Results by the method were compared to the Van Slyke gasometrie determinations. The procedure is simple, and subject to an error of about u %. This method appears to be the most satisfactory for routine use. C. A. F. THE EFFECT OF METHEMOGLOBIN ON THE EQUILIBRIUM BETWEEN OXYGEN AND HEMOGLOBIN. R. C. Darling and F. J. W. Roughton. Am. J. Physiol., 6-68, 1942.. Experiments were performed on ox and on human blood. The methemoglobin was made by aerobic oxidation, by ferricyanide, or by nitrite. The presence of methemoglobin caused a shift in the oxygen dissociation curve to the left, qualitatively the same but not as great as that produced by carbon monoxide. The shift was reversible once the methemoglobin had reverted to the ferrous form. The authors conclude that ‘ this newly discovered effect means that in methemoglobinemia the tissues are liable to anoxemia, not only from loss of oxygen capacity of the blood, but also from increasing difficulty in the unloading from the blood of such oxygen as is available.’ The mechanism is believed to be the formation of compounds intermediate between reduced hemoglobin (entirely ferrous) and methemoglobin (entirely ferrie), the conversion of one or more of the four ferrous atoms in the hemoglobin molecule to the ferric valence leading to an increased affinity of the remaining ferrous atoms for oxygen. C. A. F. THE COMPARATIVE ANOXEMIC EFFECTS FROM CARBON MONOXIDE HEMOGLOBIN AND METHEMOGLOBIN. D. Lester and L. Granberg. J. Pharm. & Exper. Therap., 8i: ,8i-u88, 1944. Carbon monoxide hemoglobin and methemoglobin, both functionally inert, would seem to differ physiologically only in the degree to which they shift the oxygen dissociation curve and interfere with normal tissue oxygen exchange. In this study the levels of these pigments at which death occurred are re448 For personal use only. on August 15, 2017. by guest www.bloodjournal.org From