Abstract
This drug causes a rise in the blood pressure of rabbit. The site of the action is believed to be in the vagal center. The blood-vessels of the rabbit's ear are either dilated or constricted. The frog's heart in situ is generally depressed with eventual heart-block. In the experiment on the isolated heart in toto and on the sinus preparations this is also the case, while the strips of ventricular muscles are stimulated by a low concentration of it. The inhibitory action on the isolated heart may be ascribed to the decreased irritability of the excitomotor area, and partially to the effect either on the heart muscle or on the parasympathetic nerve. The action on the isolated rabbit's heart is similar to that on the frog's. On the respiration this drug exerts a stimulant action and on the isolated intestine and uterus (rabbit and dog) a depressant but sometimes stimulant action. These actions seem to be atributable mainly to the effect on the muscle itself and in part to the effect on the parasympathetic mechanism.
