Hæmatoporphyminuria and its relations to the source of urobilin / by David Fraser Harris.

  • David Fraser Fraser-Harris
Date:
[1898]
Catalogue details

Licence: Public Domain Mark

Credit: Hæmatoporphyminuria and its relations to the source of urobilin / by David Fraser Harris. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    7/10 (page 389)
    Now, M'Munn made urobilin artificially by (1) oxidising haematin by the action of peroxide of hydrogen, and (2) subse- quently briefly de-oxidising it with sodium amalgam (c/. his last- mentioned paper): what have we in the body but these very two processes, for whether the haematin be freed of its iron in the liver, or be so in the muscles, skin, and connective-tissues, the pigment-antecedent so formed passes in both cases to the lungs, where it must be thoroughly oxidised, and then, during excretion by the renal epithelium, would suffer a subsequent brief reduction. It may be supposed that the chromogen of urobilin is already formed when the substance reaches the lungs, and that it is there oxidised (more or less perfectly) to the pig- ment, which, in the kidneys, undergoes a partial de-oxidation to the chromogen. (It is a familiar fact that urine deepens in colour as it stands after being passed: this may be due to a partial re-oxidation of the chromogen.) We are now in a position to inquire under what conditions uro-hsematoporphyrin supplants urobilin, wholly or partially, as the urinary pigment. Heematoporphyrin, as we know it in the laboratory, is either an acid or alkaline solution of iron-free hsematin. Acid-heemato- porphyrin can be rapidly made by adding a very little defibrin- ated blood to an excess of strong sulphuric acid. This gives the two-banded spectrum—one thin band to the left of D, and one much broader, darker band to the right of D, there being intermediate a narrow zone of obscured yellow light. There is no band at F. This pigment can be precipitated by the addition of water, and then dissolved in ammonia, giving alkali-haematoporphyrin with a four-banded spectrum. Uro-haematoporphyrin, as found in urine, has a four-banded spectrum closely resembling the last mentioned, but with this important difference, that the left of the two bands between D and E is much fainter in the former pigment; but M'Munn has managed to manufacture in the laboratory a pigment from htematin which yields by successive reductions haematoporphyrin (acid or alkali) and uro-haematoporphyrin. When his chief paper on haematoporphyrin was published he had not met with his cases of meio-de-oxy-haematoporphyrin, but he has since assigned VOL. xxxi. (n.s. vol. xi.) 2 c