Abstract
This work grew out of previous studies showing that ischemia of the functioning heart leads to a marked rise in the potassium content of the coronary venous blood. 1 This report is concerned primarily with the effects produced in anesthetized dogs on clamping off the tracheal cannula for periods of from 2 to 4 minutes. Twelve dogs anesthetized with nembutal were used. In half the dogs only one asphyxial period was produced, in the others 2 or more were obtained. Blood was drawn from the external jugular vein in 10 of the dogs. In 2 dogs the chest was opened and artificial respiration administered, the blood being obtained from the superior cava in one and from the right auricle in the other. The method of Breh and Gaebler 2 was used in the potassium determinations, the analysis being completed by the diazotization procedure of Briggs. 3 The condition of the blood samples was unknown to the analyst, since they were given blind numbers when they were drawn.
The results are given in Table I. They show that during asphyxia the plasma potassium increases 22% and the whole blood potassium 16% over the normal control values. There is an increase of 43% for the plasma and 14% for the whole blood potassium during a second asphyxial period, as compared to its control taken immediately before. The second asphyxial period was produced from 10 to 20 minutes after the first one.
These figures show the increase in blood potassium during asphyxia. Data on the effects of over-ventilation are as yet inconclusive. Fenn has shown that muscular activity causes a decrease in muscle potassium. 4 Presumably this would be accompanied by an increase in blood potassium. Producing in the anesthetized dog by reducing the cerebrospinal fluid calcium ions or increasing the potassium ions in the cerebrospinal fluid, 5 has caused a rise in blood potassium in some experiments we have recently performed.
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