[Beta]-iminazolylethylamine : a depressor constituent of intestinal mucosa / by G. Barger and H.H. Dale.

  • Barger, George, 1878-1939.
Date:
[1911]
Catalogue details

Licence: In copyright

Credit: [Beta]-iminazolylethylamine : a depressor constituent of intestinal mucosa / by G. Barger and H.H. Dale. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    The hypothetical vaso-dilatin must, therefore, be regarded as con- sisting of at least two substances: (1) /3-iminazolylethylamine, causing fall of blood-pressure, and the other characteristic effects on plain-muscle and gland-cells, but not affecting coagulation of the blood. (2) Another substance, or other substances, which render the blood incoagulable and which may or may not play some part in the other effects. - We have no evidence with regard to the origin of the /3-I. in the extract of intestinal mucosa. All possible precautions were taken to avoid putrefaction before the material was worked up: moreover a piece of intestine removed immediately after death, or even during life from an anaesthetised animal, washed, scraped and worked up immediately gives an extract with the characteristic physiological action of /3-I. Bayliss and Starling1 showed that the “depressor substance” could be extracted from fresh mucous membrane of dog’s intestine by alcohol. It must probably, then, be regarded as a normal product of intestinal mucosa, though whether it is present in living cells, or only formed when these are killed and disintegrated, remains uncertain. We have made no chemical examination of the similarly acting extracts of other organs, but it seems highly probable that the same base would be found in them. We may mention, in this connection, that we have found the widely varying vaso-dilator action of different samples of “ peptone ” to run parallel with their activity on the isolated uterus. It may be desirable to emphasise the fact, already dealt with by Dale and Laidlaw, that this constituent, at least, of “vaso-dilatin,” although producing a small secretion of pancreatic juice, has an action in this direction of an altogether lower order than that of an equally depressant dose of secretin. On the other hand, the relatively very weak action of extracts of the large intestine or of “ peptone ” on pancreatic secretion may probably be adequately accounted for by their content of /3-iminazolylethylamine. The effect of the latter on pan- creatic secretion is readily abolished by atropine. Summary. Popielski’s hypothetical “ vaso-dilatin ” contains /3-iminazolylethyl- amine, which base, however, does not affect the coagulability of the blood. 1 This Journal, xxvm. p. 335. 1902.