抄録
(1) In cats, which were previously treated with daily successive hypodermic injections of adrenaline for some weeks, the administration of a minute quantity of adrenaline into the carotid gives rise to constriction of the pupil, while by intravenous injections no such paradoxical effect is obtained. This reversed action cannot be imitated by electric stimulation of the cervical sympathetic nerve. It fails also after removal of the superior cervical sympathetic ganglion.
(2) In the pupil of such treated animals constriction is usually observed after the instillation of adrenaline.
(3) The paradoxical action of adrenaline on the pupil occurs only rarely in animals previously not treated with repeated administrations of adrenaline.
(4) In animals previously treated daily for some weeks with successive instillations of adrenaline instead of hypodermic administrations the instillation of adrenaline is always followed by weak miosis lasting for 5-8 hours. The instillation of cocaine or pituitrin provokes distinct mydriasis in the previously treated eye and of physostigmine less marked miosis in the eye on this side than in that on the non-treated side.
(5) The paradoxical action is based probably on the altered chemism of the dilatator muscles of the pupil.
