On urobilin / by Archibald E. Garrod and F. Gowland Hopkins.

  • Garrod, Archibald E. (Archibald Edward), Sir, 1857-1936.
Date:
[1896]
Catalogue details

Licence: Public Domain Mark

Credit: On urobilin / by Archibald E. Garrod and F. Gowland Hopkins. 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.

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    similar results, and there appear to be strong reasons for thinking that this is the ordinary mode of formation of urobilin in the animal body, although the possibility that hasmoglobin may, under certain circumstances, be directly converted into urobilin, without passing through the stage of bilirubin, cannot yet be excluded. That urobilin occurs in excess in the urine when extravasations of blood are being absorbed, and also when an unusually active haemolysis is in progress must be regarded as an established fact. Of the many observers who have contributed to our knowledge of urobilin the majority have devoted special attention to the mode of origin of the pigment and the clinical significance of its presence in the urine in excessive amount, whilst others, who constitute a much smaller group, have chiefly studied its chemical and spectroscopic properties. We do not propose to enter here upon any discussion of the rival theories of urobilin formation which have been so ably advocated by F. Muller, Riva, Hayem, and many others, as these theories lie outside the province of the present investigation. MacMunn maintains that the urobilin of normal urine, although exhibiting an absorption band between h and F, and yielding a green fluorescence with zinc chloride and ammonia, is a distinct substance from that which yields the conspicuous band seen with many morbid specimens, and believes that whereas the latter is a reduction product of the bile and blood picrments, the former is an oxidation product. He bases the distmction chiefly upon the presence of certain extra spectroscopic bands, and on differences in the character of the essential urobilin band. Eichholz and Adolf JoUes^ have more recently drawn a similar distinction between normal and pathological urobilin, but their desci'iptions of the two pigments do not accord with each other, or with those ot MacMunn. , In this, the first, instalment of our paper we propose to describe a series of observations and experiments directed towards the following °^^T''The extraction of urobilin from urine in as pure a condition as possible by processes free from the objections which may be urged against those hitherto employed. 2 The study of the properties of the pigment so extracted .S' The comparison of the urobilin of normal and morbid urines with that obtained from other sources within the body.