The soluble ferments and fermentation.

  • Green, J. Reynolds (Joseph Reynolds), 1848-1914.
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: The soluble ferments and fermentation. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    ferments. Indeed evidence lies ready t.. Ii.iiid that this is not the case. If a pancreas is removed tVum a fasting dog immediately after death and al onct- extracted with an appropriate solvent, the resulting extract has little or no fermentative activity. If however it is kept warm for a few hours, and particularly if it is faintly acidified, the extract will be very powerful. If the extract made immediately after death is acidified and kept warm for some time, it will become active. The material extracted from the gland cells, which we have seen to be connected with, if not composed of, the granules, is not the enzyme, but something which rapidly gives rise to it when warmed with a trace of acid. This antecedent substance has been named mother of ferment or zyinorjen. There appears to be for each enzyme a distinct antecedent or zymogen, in which form it is stored in the cells, ready to be transformed into the active ferment directly it is required. This change seems to take place immediately prior to, or perhaps during, its extrusion from the cell. We see thus that we can recognize in the secretion of en- zymes a gradual process, at least one antecedent body being formed. Are we able to investigate this process more closely ? In the recital of the changes in the cells, we have noticed almost always that the nucleus has appeared to play a part in the secretion, though what its function is has not so far been apparent. We may recall here the observation of Brown and Morris on the scutellar secretion of diastase. This is a process which is continuous after its first inception, and not inter- mittent like that of animal glands. It will be remembered that w^hen the secretion has ceased and the granularity of the cells has disappeared, the nucleus is found to be disintegrated. Some extended researches upon this point have been carried out by Macallum in connection -with an enquiry into the distri- bution of iron and phosphorus in cells generally. His experiments were carried out on the pancreas of several animals, by means of staining reagents w^hich coloured differently the various parts of the cytoplasm and nucleus, and also of cer- tain special reagents capable of detecting iron and phosphorus. Using eosin, he found that at a time coinciding closely with the