The action of thionyl chloride and of phosphorus pentachloride on the methylene ethers of catechol derivatives / by George Barger.

  • George Barger
Date:
[1908?]
Catalogue details

Licence: Public Domain Mark

Credit: The action of thionyl chloride and of phosphorus pentachloride on the methylene ethers of catechol derivatives / by George Barger. Source: Wellcome Collection.

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    sympathetic or thoracico-lumbar division of the autonomic system. An examination of the action of pituitary extract on various organs and systems containing plain muscle and gland-cells will indicate whether its action has more than a superficial resemblance to that of adrenaline by showing whether its effects, or any group of them, can be similarly summarised by relating them to a particular element of the visceral nervous system. Incidentally evidence will be discussed which throws light on the contention of Schafer and Herring that two active principles exist in the extract, one acting on the circulatory system, the other specifically on the kidney. The extract used in my experiments, except where otherwise stated, was a 5 per cent, decoction of the fresh posterior lobes of ox pituitaries. The posterior lobes were dissected clean from the rest of the gland and from dura water, weighed in the moist condition, pounded with sand, and boiled with water faintly acidulated with acetic acid to produce coagulation. The extract, filtered from coagulum, is a clear colourless fluid giving a faint biuret reaction. For experiments on isolated organs the extract was prepared with Ringer’s solution and carefully neutralised before use. II. The Effect ox the Circulatory System It has been mentioned that pituitary extract causes a striking rise of blood-pressure, chiefly due to arterial constriction. If the action had any relation to innervation by the sympathetic system we should expect to find that the effect on the arteries was accompanied by an increased frequency and force of the heart-beat, corresponding to the effect of the cardio-accelerator nerves. It was pointed out by Schafer and Oliver that this was not the case: the beat of the heart usually becomes slower, even after exclusion of vagus action, though it may be somewhat augmented. Reference will be made later to the action of the extract on the isolated heart, which enables the effect to be studied in its least complicated form. We should further expect to find, if the action were like that produced by sympathetic nerve-impulses, that the action on the arteries showed irregularities of distribution corresponding to that of sympathetic nerves. It was of special interest, therefore, to examine the action on those arteries which have been shown to be exceptional in their innervation and in their reaction to adrenaline. The 'pulmonary arteries. Brodie and Dixon showed that the peripheral branches of the pulmonary artery are exceptional in that their
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