THE SUPRARENAL SYSTEM 207 



agency of any other substance. I found that, in pregnant 

 animals, the intravenous injection of adrenalin was frequently 

 followed by abortion. If, in the later stages of pregnancy, a prem- 

 ature birth is obtained by artificial means, it is usually accom- 

 panied, at least as far as my experience goes, by serious, or 

 even incurable, haemorrhage. The intravenous injection of 

 .1 mg. adrenalin will, however, immediately arrest such haemor- 

 rhage. It will be seen by direct inspection that adrenalin pro- 

 duces a high degree of contraction of the uterine muscles as well 

 as of the vessels, and this is sufficient to account for the 

 cessation of the haemorrhage. Adrenalin not only produces 

 uterine contractions, but it increases the excitability of the organ 

 to such a degree, that it reacts to direct or nervous stimuli to 

 which it was previously insensitive. 



The specific action of adrenalin upon the uterine muscles was 

 turned to account by Neu in the therapeutics of obstetrics. He 

 recommended the direct injection of adrenalin into the substance 

 of the relaxed and enlarged uterus. By this means the desired 

 contraction was obtained, while the possible ill-effects of intra- 

 venous injection were avoided. I have found from personal 

 experience that the method is free from objection. 



The action of adrenalin upon the living uterus is also seen 

 after the removal of that organ from the body. Acconi, and 

 after him Franz, proved the effects of certain pharmacological 

 reagents upon both the automatic movements of the uterus, and 

 upon portions of extirpated uterine tissue obtained from man and 

 animals. Kurdinowsky next discovered that it was possible to 

 prolong the life of the uterus of a rabbit for days at a time by 

 the transfusion of Locke's fluid into the aorta. He found that 

 adrenalin, even in very weak solutions, acts more powerfully upon 

 the uterus than any known substance. By adopting Magnus's 

 method with the intestine, Kehrer obtained graphic tracings of 

 the spontaneous movements of the uteri of rabbits and cats. 

 Still more recently, A. Fraenkel employed the uterus removed 

 from the living body of rabbits as a quantitative test of adrenalin. 

 He found that adrenalin solutions reacted upon portions of the 

 uterus in such a manner as to produce a specific change in the 

 curve of the spontaneous contraction-waves. The lever rises 

 rapidly and very decisively to a point above the summit of the 

 highest normal wave; it remains in this position for several 

 minutes, oscillating slightly; and then falls slowly to the abscissal 

 line, at the same time making wide oscillations. The curve 

 produced by the action of adrenalin is the expression of the 

 transitory maximal contraction effected by this substance. This 

 contraction takes the form of a tonic stimulation, starting promptly 

 and increasing slowly until, in some instances, a tetanic condition 

 obtains. According to Fraenkel, and I am in a position to 

 confirm his results, the uterus of rabbits responds to an adrenalin 



