Abstract

Experiments made upon the intact uterus of dogs anesthetized with morphine and chloretone have yielded the following results:

1. The tone of the uterus was found to vary inversely with the salt concentration of the blood when altered by intravenous injections.

2. The above changes were found to be independent of the blood pressure for hypo- and isotonic solutions sometimes raised and sometimes lowered the blood pressure while the effect on uterine tone was constant. Although hypertonic sodium chlorid always reduced the blood pressure simultaneously with the relaxation of the uterus the former recovered independently of the latter, and 14 per cent acacia injections which increased the blood pressure were none the less efficient in diminishing uterine tone.

3. That the effects of saline injections were not due to changes in the blood volume is shown by the transfusion as well as the hemorrhage experiments, for the former affected the tone of the uterus differently in each case and the latter was without effect upon it.

4. Isotonic sodium chlorid injections occasionally increased the uterine tone; also when 3 or 7 per cent acacia was added. These effects were always associated with some rise of blood pressure, a phenomenon which does not necessarily affect the uterine tone.

5. Injection of whole blood (transfusion) increased the rate of uterine contractions, while loss of blood abolished them.

6. When acids or alkalies were injected the tone of the uterus varied in the same direction as the hydrogen-ion concentration of the blood.

7. A number of clinical applications of the above work have been suggested.