Studies on rheomelanins. IV. The apparent occurrence in vivo of rheomelanins in human blood.

Paper chromatograms of the rheomelanins made earlier in this laboratory in human plasmas during incubation with each of the catecholamines or with L-dopa had yellow-green fluorescence in ultraviolet light of 366 nm (Hegedus & Altschule, 1970). In the present studies, a yellow-green fluorescent spot was found in each paper chromatogram. All of these spots were eluted and their excitation and emission spectra were recorded and compared to one another. The rheomelanins made from the catecholamines, L-dopa, catechol or from mixtures of these in human plasmas during incubation were chromatographed twice on paper with two different solvent systems. These artificial rheomelanins in vitro and the apparent in vivo rheomelanins present in plasmas moved together during the two chromatographies. These yellow-green fluorescent compounds were eluted as one spot after the second chromatography. This mixture produced high intensity excitation and emission spectra closely similar to the low intensity excitation and emission spectra of the apparent in vivo rheomelanins of unincubated human plasmas treated the same way without any chemical under nitrogen. The RF-values of the various rheomelanin spots after each chromatography were closely similar. These above results were also obtained with other solvent systems. It appears therefore that rheomelanins are formed in vivo in the human body.     

Studies on rheomelanins. V. Hemolysis associated with the transformation of catechol into rheomelanin in human blood.

Incubation of 2 mg amounts of catechol in 5 ml samples of heparinated blood plasma from four subjects at 38 degrees C for 24 h produced plasma-soluble rheomelanins. These solutions had the brown color and the yellow-green fluorescence in ultraviolet light of 366 nm of other rheomelanins. Their differential ultraviolet and visible spectra showed a rheomelanin absorption maximum at 344 nm. Paper chromatograms of the rheomelanin-plasma solutions in 5% methanol-95% water showed elongated spots of rheomelanins with RF values of 0.82, on Whatman No. 1 paper. Using heparinated distilled water adjusted to pH 7.4 with sodium bicarbonate instead of human blood plasma gave markedly different findings from those obtained with the plasma rheomelanin solutions. Incubation of 4 mg amounts of catechol in 10 ml samples of heparinated whole blood from four subjects for 24, 32 and 48 at 38 degrees C produced rheomelanins as found in the plasma separated from the blood after incubation. The differential ultraviolet and visible spectra of these solutions revealed hemolysis caused by the catechol rheomelanins; this was more marked with longer incubations. The hemolysis was manifested by two absorption peaks at about 270 and 400 nm. Paper chromatography revealed the brown elongated spots of catechol rheomelanins with an RF value of 0.82. Other spots owing to the products of hemolysis were also present.     

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Carved from the Heart.

Carved from the Heart. 1997. 30 minutes, color. VHS. film by Ellen Frankenstein and Louise Brady. For more information, contact New Day Films, 22D Hollywood Avenue, Hohokus, NJ 07423. 201/652-6590 or 888/367-9154. Fax 201/652-/973. Email: orders@newday.com, website: http://www.newday.com