抄録
In the cat, the upper cervical sympathetic ganglion or which was removed one to two weeks before, the intravenous minimum effective dose for producing the paradoxical pupil dilatation was measured for acetylcholine and nicotine. Cats were not anesthetised or fastened.
(1) The threshold doses of both drugs were pretty uniform during this period, such as from one week to two weeks after the ganglionec-tomy. It was approximately 0.0007mg. per kilo for acetylcholine and 0.01mg. per kilo for nicotine. (The drugs were injected not at once, but with a regular interval of discontinuation.) We are here interested of the ratio of doses of both drugs chiefly.
While a similar ratio of both drugs is noted in a previous paper dealt with epinephrine secretion in cats, a rather reverse ratio has been reported in some papers with like kind of researchs with the latter but in dogs.
(2) Double sectioning the splanchnic nerves, carried out two weeks to two months before, lessened distinctly the threshold dose of acetylcholine, but did not alter that of nicotine.
(3) Removal of the suprarenal medulla, done two weeks to two months before, enlarged definitely the threshold dose of acetylcholine and of nicotine, particularly largely the former.
Occurrence of the paradoxical pupil dilatation by the drugs, es-pecially by nicotine, after excluding suprarenal capsules or splanchnic nerves, was that missed by most of previous investigators.
