On the action of ergotoxine : with special reference to the existence of sympathetic vasodilators / by H.H. Dale.

  • Dale, Henry Hallett, 1875-1968.
Date:
1913
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Licence: In copyright

Credit: On the action of ergotoxine : with special reference to the existence of sympathetic vasodilators / by 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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    ON THE ACTION OF ERGOTOXINE ; WITH SPECIAL REFERENCE TO THE EXISTENCE OF SYMPA- THETIC VASODILATORS. By H. H. DALE. (From the Wellcome Physiological Research Laboratories, Herne Hill.) The observation, that small closes of adrenine have frequently a depressor instead of the more familiar pressor action, is probably common to the experience of many who have had frequent occasion to observe the action of varying doses of this substance on the blood- pressure of carnivora. Several observers have recorded the phenomenon incidentally (Cushny1, Elliott and Durham2, Chiari and Frohlich3). Cannon and Lyman4, who, in a recent paper, discuss the meaning of the effect, and emphasise its importance in the regulation of blood- pressure under normal conditions, quote a number of other publications in which it is mentioned. They show clearly that it is not due to decomposition products or other impurities, but is a vasodilator effect of adrenine itself, and regard it as analogous to the vasodilator action produced, by any dose of adrenine, after ergotoxine has been given. This has always been my own assumption, when I have observed this normal vasodilator effect of adrenine, but I have been inclined to interpret the somewhat variable effect in the normal animal in the light of the relatively constant effect seen after ergotoxine. Cannon and Lyman appear to argue in the reverse direction, and, finding that the vasodilator action in the normal animal is only obtained when the arterial tension is above a certain critical level, conclude that the action of ergotoxine is simply to raise the arterial tension above this critical level, when it has been otherwise depressed. Such a rise of arterial tone is undoubtedly a factor in the apparent effect of small doses of 1 This Journal, xxxvn. p. 137. 1908. 2 Ibid, xxxiv. p. 494. 1900. 3 Arch. f. exp. Path. u. Pharmakol. lxiv. p. 214. 1911. 4 Amer. Journ. of Physiol, xxxi. p. 376. 1913.