The effect of vagus inhibition on the output of potassium from the heart / by W.H. Howell and W.W. Duke.

  • William Henry Howell
Date:
[1908?]
Catalogue details

Licence: Public Domain Mark

Credit: The effect of vagus inhibition on the output of potassium from the heart / by W.H. Howell and W.W. Duke. Source: Wellcome Collection.

    3/20 page 51
    Reprinted from the American Journal of Physiology. Vol. XXI.— February 1, 1908. — No. I. THE EFFECT OF VAGUS INHIBITION ON THE Clr) OF POTASSIUM FPEOM. TEE HEART. BY Wy H. HOWELL ann WoW. DUKE. [From the Physiological Laboratory, Fohns Hopkins University, Baltimore, U.S. A. [* a previous paper one of us has advanced the hypothesis that the vagus fibres of the heart “end in what may be designated as an inhibitory substance which, under the influence of the vagus im- pulses, is dissociated with the liberation of potassium compounds to which the phenomenon of inhibition is directly due.” * To test this hypothesis, namely, that the phenomenon of vagus inhibition is at bottom a case of potassium arrest, the present authors have attempted to determine directly the influence of repeated stimula- tion of the vagus upon the potassium output in the mammalian heart. For this purpose the heart was isolated, in dogs, rabbits and cats, and kept beating upon a large supply of Locke’s solution, fed to the heart through the coronary arteries under oxygen pres- sure. From time to time the circulation of the stock liquid was suspended and the heart was inhibited for one-half minute to a minute by stimulation of the vagus in the neck, or, as was fre- quently necessary, by stimulation of a branch from the level of the inferior cervical ganglion on the right side. At the end of the stimulation the heart was washed out through its coronary arteries by a special supply of the circulating liquid, amounting to 75 to too c.c. The vagus fibres were stimulated as often as they con- tinued to give a visible inhibition of the auricles, that is, in the different experiments, from five to twenty times, and after each inhibition the heart was irrigated by the same special supply of circulating liquid. At the end of the experiment samples were taken of the circulating liquid which had passed once through the unstimulated heart, and of the special supply which had been cir- culated repeatedly through the heart after inhibition, and these samples were analyzed for their content in potassium. Control 1 HoweEL.L, W. H.: This journal, 1906, xv, p. 280. See also MARTIN: This journal, 1904, xi, p. 370, and Botazzi: Archives de physiologie, 1896, p. 882.
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