The depressor effect of adrenalin on arterial pressure / by W.B. Cannon and Henry Lyman.

  • Walter Bradford Cannon
Date:
[1913?]
Catalogue details

Licence: Public Domain Mark

Credit: The depressor effect of adrenalin on arterial pressure / by W.B. Cannon and Henry Lyman. Source: Wellcome Collection.

    6/28 page 379
    not always increase arterial tension, but, in small doses, may indeed lower the tension. The almost direct fall in the blood pressure record reproduced in Fig. 1, B is therefore due to the liberation of adrenalin from the adrenal glands when the splanchnic nerves are stimulated. In spite of the foregoing evidence the idea is firmly fixed that adrenalin is normally an agent raising blood pressure by vaso-con- striction. For example, Biedl, in his summary of the literature on the ductless glands, describes, as the most important and most char- acteristic of the physiological effects of adrenalin, its action in rais- ing blood pressure, and although mentioning the secondary fall observed in some animals states that the rise occurs even with mini- mal doses.” Vincent likewise has testified that although he has frequently employed very small doses, he has never seen the depres- sor effect of adrenal extract.” THE OBJECTS AND METHODS OF THE PRESENT INVESTIGATION. An investigation of the depressor action of adrenalin is important for several reasons. As already shown, the adrenal secretion poured out in the first moments of stimulation of splanchnic nerves causes blood pressure to fall. Depression due to adrenalin may therefore be a common phenomenon in conditions affecting these nerves, as strong sensory stimuli, pain, and major emotional states. Further- more, the widespread conception that adrenalin is strictly vasopres- sor in action warrants a consideration of its depressor function. And, finally, because adrenalin mimics the sympathetic system, which is usually regarded as vasopressor, the vasodepressor action should be carefully considered. For these reasons the investigation here re- ported was undertaken. Although Meltzer observed vasodilation of the rabbit’s ear after a small subcutaneous injection of adrenalin, we have not been able to produce in the rabbit a fall of blood pressure with any dose, even the most attenuated. We have found no reference in the literature 2 BreDL: Innere Sekretion, Berlin and Vienna, 1913, second edition, i, pp. 429- 430. 18 VINCENT: Loc. cit., p. 174.
    digitised image 1
    digitised image 2
    digitised image 3