抄録
The authors have carried out experiments on animals with the alkaloid “ Leonurin ” isolated from Leonurus sibiricus, L. ?? and they have come to the following conclusions :
1. Leonurin when subcutaneously injected into frogs causes a central paralysis, and the minimal lethal dose of Leonurin per 1 gm. of body-weight of the frog is estimated to be between 0, 0004 and 0, 0006.
2. Leonurin when injected into mice causes an irritation in the first stage, followed by cramp, and later by respiratory paralysis. The heart may be seen to beat for some time after respiration has ceased.
The minimal lethal dose of Leonurin for a mouse per 1 gm. body-weight seems to be between 0, 0006 and 0, 0007.
3. An injection of Leonurin into the vein of a cat causes a temporary fall of blood pressure, but sometimes it is followed by a slight rise. This effect seems to be due to the peripheral action of the substance.
4. A certain amount of Leonurin is apparently not toxic as far as the heart is concerned. In an experiment with an excised frog's heart, it was observed that a small amount of Leonurin had a rather stimulative action, but an excessive dose a paralysing effect.
5. In a perfusion experiment with Leonurin on a toad, a contraction of the blood vessels was observed, and almost the same results but in a less marked degree, were seen in experiments with several organs of a rabbit.
6. A small amount of Leonurin, when intravenously injected into a cat acts as a stimulant upon the respiration, quickening the frequency and magnifying the amplitude, but an excessive doses causes, after a temporary stimulation, a paralysis, the respiration becoming weaker and irregular. This effect is due to the action of the substance upon the respiratory center.
7. Leonurin paralyses the motor nerve endings of a frog as “Curara” does.
8. The excised small intestine of a rabbit is influenced by a small amount of Leonurin in such a way that the tonus is relaned and the amplitude of the movement magnified, while an excessive dose acts rather inhibitorily. This effect is considered to be due to the action of the substance upon the intestinal muscle itself.
9. The excised uterus of a rabbit is influenced by Leonurin so that the tonus is increased and the amplitude of the movement magnified.
10. Leonurin when injected into the veins of a rabbit, causes a marked diuretic action.
11. Leonurin when added to the blood of a rabbit causes a haemolytic action up to the concentration of 1: 1000.
