Abstract
1. Apomorphine acts in the smallest dose by intravenous injection, next when given intramuscularly, then sub-cutaneously, and the largest dose is required by stomach. This is to be taken as an indication that the drug acts only after its entrance into the circulation.
2. Vomiting occurs much more rapidly after intramuscular injection than when the drug is introduced directly into the stomach which is not in accordance with local action, but which rather implies a slower rate of absorption from the stomach than from the muscles.
3. Dilution within reasonable limits does not influence the size of the effective dose by stomach as would probably be the case if the action were a local one.
4. The uniformity of the dose by a given channel of introduction suggests that the action is upon a highly specialized structure such as a portion of the central nervous system.
5. The development of a "refractory state" by a slight excess during intravenous administration is not easily explained except upon the basis of direct central action.
6. The absence of the drug in a free state and unchanged in the vomitus is against the occurrence of a reflex action after excretion.
7. The removal of the gastro-intestinal tract does not prevent the production of emesis by apomorphine, hence the drug must act elsewhere than upon this structure.
8. After the removal of the gastro-intestinal tract and cocainization of the oesophagus and pharynx apomorphine still causes typical vomiting movements. This is strong evidence that the drug does not act after vicarious excretion into the oesophagus.
9. The absence of emesis and of absorption from the oesophagus of eviscerated animals when apomorphine is allowed to remain in this structure for an hour would seem to exclude the occurrence of local action.
10. Absence of any evidence in favor of local action.
Upon the evidence to be obtained from the literature and that which we have presented from our own experimental observations we would draw the following
Footnotes
- Received April 23, 1912.
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