The significance of the supra-renal capsules in the action of certain alkaloids / by H.H. Dale and P.P. Laidlaw.

  • Dale, Henry H. (Henry Hallett), 1875-1968.
Date:
[1912]
Catalogue details

Licence: Public Domain Mark

Credit: The significance of the supra-renal capsules in the action of certain alkaloids / by H.H. Dale and P.P. Laidlaw. Source: Wellcome Collection.

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    even in the virgin; for the pilocarpine effect is absolutely resistant to ergotoxine, though immediately abolished by atropine. (Fig. 2.) The action is, indeed, very similar to that which pilocarpine exerts on the plain muscle of such organs as the bladder or intestine, receiving motor fibres from the oro-anal autonomic system, or the retractor penis of the dog or goat, receiving motor fibres from the true sympathetic. If the uterus had a motor supply from the pelvic nerves, the effect of pilocarpine would be attributed to action on the “ nerve-endings ” or “ myoneural junctions ” corre¬ sponding thereto, and would furnish another instance of the reproduction of oro-anal autonomic effects by this alkaloid. As it is, no such association can be suggested, unless it be supposed that the uterus has developed a sensitiveness to, or “ receptive substance ” for pilocarpine, in anticipation of a union with pelvic nerve fibres, which has not, in fact, taken place. We have, then, in the case of all the alkaloids re¬ ferred to above, an effect on the cat’s uterus resembling that of sympathetic nerve stimulation; but this effect, unlike that of adrenine and the other sympathomimetic amines, does not survive excision of the organ. Several of them have, in addition, a direct motor action on uterine muscle; but the sympathetic effect, when inhibitor, is usually powerful enough to mask this when the uterus is observed in situ. The sj^mpathetic effect appears to be in all cases peripheral in origin, since it is not affected by severing the hypogastric nerves, and thereby interrupting the main nervous path to the uterus. We have not found it practicable to make certain of dividing all the post-ganglionic fibres without interfering with the circulation to the uterine horn ; so that the possibility would appear to be open that these alkaloids produce their sympathetic effects by stimulating the peripherally placed ganglia, which are so situated as to be left behind in excising a uterine horn carpine. R—fresh Kinger.