Abstract
Since it was necessary to carry out a part of this investigation under ether anesthesia, it was first necessary to establish type graphs of the concentrations of Ca, K, P, Na, and of Mg during 2 hours of ether anesthesia. This was done on 20 normal dogs. The results in general conform well with those reported by other investigators.
In a second series of 13 dogs, anesthesia was induced after a sample of heart blood was taken. Both vagi were then isolated and shielded electrodes from a common inductorium attached. The intensity of current was adjusted so that neither heart rate nor respiration were markedly affected. In no case was the former decreased more than 5 beats per minute. It is believed that this represented a stimulus of physiological intensity. A tetanizing current so adjusted was applied for 30 minutes after which a second blood sample was drawn, and a third at the end of another hour. In a third series of 8 dogs similar technic was employed except that both vagi were sectioned and the electrodes were applied to the peripheral ends. The composite graphs constructed on a percentage basis are shown in the accompanying figures. With exception of potassium the responses in the individual experiments conformed well with the composite graphs which may, therefore, be considered as type graphs.
It is recognized that the anesthetic is a complicating factor and that these experiments merely demonstrate the modification of the anesthetic graph by vagal stimulation.
The differences observed between peripheral vagal stimulation and intact vagal stimulation may be ascribed to antagonistic reflexes aroused by impulses conveyed centrally from the point of stimulation in the latter group of experiments. A point of some interest is the similarity of all the graphs for calcium to those for potassium.
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