Formation of urobilin / by Vaughan Harley.

  • Harley, Vaughan.
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: Formation of urobilin / by Vaughan Harley. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    conditions a diagnosis may be founded on the increase in the quantity of urobilin in the urine, a solution to the question of in what part of the organism it is formed is of very great importance, and the following is a brief summary of the theories that have been propounded up to the present. 1. Hepatogenous Urobilin—The French are the chief sup- porters of this theory. They consider that instead of under normal conditions the liver cells forming bilirubin they form urobilin when they are diseased. The presence of an increase of urobilin in the urine they therefore consider arises from hepatic insufficiency. 2. Hematogenous Urobilin.—The supporters of this view con- sider the liver has nothing to do with the formation of uro- bilin, and that it is directly derived from tlip red blood cor- puscles which are broken up in the circulating ~>d either by some chemical or toxic poison. Or it may be that the breaking up of the red corpuscles in large extravasations yield urobilin to the circulation, which, like any other foreign substance, is eliminated from the blood by the kidneys. 3. Nephrotic Urobilin.—Those who believe that the kidney is the source of urobilin consider that bile from any cause, after reaching the general circulation, is converted into uro- bilin during the process of its elimination by the renal epi- thelium, and then finds its way into the urine. According to the quantity of bile that is to be eliminated, all or only part of it is converted into urobilin, and this explains why uro- bilin may be increased when bile pigments are absent, or nearly so. 4. Histogenic Urobilin.—In the same way as in the last view the bile in the organism itself is believed to be the precursor of the urobilin. The bile pigment, after having reached the general circulation, and being deposited in the tissues as in ordinary jaundice, is slowly converted into urobilin, and the urobilin being more soluble than the bile, is then dissolved in the blood and is eliminated in the urine. 5. Enterogenous Urobilin.—Maly, who long ago showed that urobilin could be formed from bilirubin by reduction outside the body, considered that in the healthy organism the uro- bilin in the urine is derived from absorption into the blood from the intestinal tract, of the urobilin that has been formed from the bilirubin in its passage along the intestines. The late investigations of Muller and his pupil, D. Gerhardt, have added strong support to this last view. Muller found a