Abstract
The frog's lethal doses in the four-hour-method and the doses to open the mouth or to cause vomiting in frogs were given with the digitalis preparations as in the table below. It has been assumed from these results that digicorin, digoxin and digitalis leaves were more rapidly detoxicated than the others. The opening motion of mouth began within several minutes after aglycones injection, while it required more than thirty minutes with the other preparations. The maximal patterns of this motion were reached within one or two hours after the administration, whereby it was even seen a few of frogs drawing their stomachs out of their mouths. The frogs, decerebrated or centrally anesthetized, opened their mouths by the digitalis adminstration, while the frogs, middle-brain or medulla removed, spinal cord destructed or anesthetized with phenobarbital, showed no reaction as such. The frogs, cardiac nerves of which had been cut, opened their mouths by the intravenous injection of digitalis preparations. The hepatectomized or gastroectomized frogs opened their mouths. From the results it is concluded that the digitalis preparations caused vomiting under the influence from the middle-brain reflex pathway, but not from the reflexes passing from the heart, liver or stomach.
