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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    methylamino-bases are relatively prominent not only as compared with those of homologous bases, in particular the amino-bases, but also in comparison with those of sympathetic nerves. All the sympathetic effects which are weakly or doubtfully reproduced by adrenine are motor effects—e.g. pilo-motor action, or contraction of the trigone of the cat’s bladder. On the other hand certain inhibitor effects, such as inhibition of the fundus of the cat’s bladder, or of the non-pregnant uterus of the same animal, are more easily and completely produced by adrenine than by nerve-stimulation. Similarly certain normally motor effects of adrenine are reversed by smaller doses of ergotoxine than are needed for the reversal of the corresponding motor effects of stimulating sympathetic nerves. In these respects the action of some of the other bases, particularly of the amino- and ethylamino-bases of the catechol group, corresponds more closely with that of sympathetic nerves than does that of adrenine. To suppose that such bases and sympathetic nerve-impulses alike owe their action to the liberation of adrenine seems to us to create additional difficulties of conception. Apart from such proximate conceptions our results have some interest in relation to the current controversy as to whether the activity of these and other bases depends ultimately on a physical or chemical process. It is, perhaps, desirable to point out, in the first place, that there is no reason why the whole of the facts should necessarily be interpreted in terms of the one class of action or the other. The most striking feature in the action of the bases under consideration is the more or less strict localisation of their action to cells innervated by a certain morphological system, on which cells they act when present in very high dilutions. There must evidently be something in those cells, or connected with them and them only, which has a strong affinity for these amines. But the property on which this affinity depends is by no means necessarily or even probably that which confers stimulant activity on the amines. In brief, the stimulant activity may depend on one property, the distribution of the action on quite a different property. The existence of pairs of bases, such as atropine and pilocarpine, the action of which has a practically identical distribution, though one paralyses where the other stimulates, makes it, indeed, impossible to regard the localisation of the activity and the existence of the activity as due to the same property. Langley1 suggests that “ it is conceivable that combinations should be formed by poisons which have no effect observable by our present methods.” If 1 Journ. of Physiol, xxxiii. p. 409. 1905.