Chemical structure and sympathomimetic action of amines / by G. Barger and H.H. Dale.

  • Barger, George, 1878-1939.
Date:
[1910?]
Catalogue details

Licence: Public Domain Mark

Credit: Chemical structure and sympathomimetic action of amines / by G. Barger and H.H. Dale. Source: Wellcome Collection.

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    is several times as active as n. butylamine : n. amylamine is again dis¬ tinctly, though not very greatly, more active than iso. amylamine (Fig. 1). The iso. amylamine in question is the base (CH3)2CH2CH2CH2NH2 which occurs as a putrefaction product of leucine. The other iso¬ meric amylamines were not available for examination: they would probably have been less active, since, in this series, the activity seems to increase with the length of the straight carbon-chain up to six carbon atoms. Of the bases above amylamine only the normal (straight-chain) representatives were available. Normal hexylamine is the most active of the normal series. Normal heptylamine is slightly, but distinctly less active (Fig. 2). With the higher members of the series comparison Fig. 2. At A, A', 1 c.c. — n. hexylamine. B, ,, ,, n. heptylamine. C, 2 c.c. ,, iso. amylamine. becomes more difficult, since they become increasingly toxic, the specific sympathomimetic effect being complicated by depressant action on the heart and by the production of convulsions of spinal origin. The direct, depressant action on the heart-muscle is perceptible even in iso. amylamine (cf. Dale and Dixon), but it does not seriously complicate the blood-pressure of the pithed animal with members of the series lower than octylamine. One dose of these higher amines greatly depresses the effect of succeeding doses, so that injections in the order ABA are no longer useful for comparison. Octylamine is definitely less active than heptylamine, but beyond that comparison