The alleged formation of adrenine from tyrosine / by A.J. Ewins and P.P. Laidlaw.

  • Ewins, Arthur James.
Date:
[1910?]
Catalogue details

Licence: Public Domain Mark

Credit: The alleged formation of adrenine from tyrosine / by A.J. Ewins and P.P. Laidlaw. Source: Wellcome Collection.

    6/8 (page 278)
    The adrenine content of the two solutions was compared physio¬ logically. The method employed consisted in determining the rise in arterial blood pressure produced in a pithed cat by intravenous injection of equal submaximal doses of the two filtrates. The rise in blood- pressure was practically the same in each case. (See Fig. 1.) If one-tenth of tyrosine added had been transformed into adrenine the effect on the blood-pressure would have been doubled. Further, if either dihydroxyphenylethylamine (step 2) or dihydroxyphenylethyl- methylamine1 had been formed the rise of blood-pressure induced by the test filtrate would have been greater than the control. As is readily seen in the figure the control is slightly higher than the test. We then incubated parahydroxyphenylethylamine with suprarenal glands under similar conditions and similarly controlled. The rises in blood-pressure were here again equal in both cases. (See Fig. 2.) If a twentieth of the added amine had been converted into adrenine the effect on the blood-pressure would have been doubled. Finally we incubated dihydroxyphenylethylmethylamine2 under similar conditions. In this case only the last step, the introduction of a hydroxyl group into the aliphatic chain, is required for the formation of adrenine. Comparison of the solution and control showed rises of blood-pressure which were the same within the limits of the experimental error. (See Fig. 3.) If one-seventh of the amine had been converted into adrenine the effect on the blood-pressure would have been doubled. We are, therefore, of the opinion that there is as yet no evidence of the formation of adrenine by ferment activity, from tyrosine or the more closely related bases parahydroxyphenylethylamine and dihydroxyphenyl- ethylmethylamine. i 1 As yet unpublished work of Dale and G. Barger. 2 For this base we are indebted to F. L. Py man. Trails. Ghem. Soc. xcvn. p. 264. 1910'.