Abstract
The impression prevails that adrenalin and pituitrin affect the body in the same direction. The most striking action is the production of a blood pressure rise by both substances. The action of both substances upon the uterus and upon the intestines are also in the same direction; the difference is only a quantitative one and it is slight. Several years ago one of us (M.) reported before this society that pituitrin acts strikingly different from adrenalin upon the pupil of rabbits on the side in which the superior cervical ganglion has been previously removed. We have recently studied the subject from various angles and wish to demonstrate the obtained results on these three rabbits. In two of these animals the superior cervical ganglion has been removed on one side several days ago; the third rabbit is a normal one. The demonstration shows the following facts. (1) The intravenous injection of pituitrin in a normal animal produces a considerable constriction of the pupil, while adrenalin produces a moderate dilatation of short duration. (2) The intravenous injection of adrenalin causes a maximal dilatation of long duration of the pupil on the side in which the ganglion was removed, while injection of pituitrin causes rather a constriction. (3) When adrenalin and pituitrin are injected simultaneously into a rabbit in which a ganglion is removed the corresponding pupil dilates, but the dilatation is much less than that of the pupil of a ganglionectomized animal which received adrenalin alone.
Two facts stand out clearly: First, the effect of adrenalin upon the pupil is dilatation, while that of pituitrin is constriction; second, with regard to their action upon the pupil pituitrin counteracts to a degree the dilating effect of adrenalin.
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