2-2-2 THE DUCTLESS GLANDS 



At the suggestion of the present writer, the experiment of 

 Strehl and Weiss has been repeated by Young and Lehmann. 

 In their experiments an attempt was made upon dogs to dam 

 back any secretion which the glands may pour into the blood- 

 stream, and after an interval to remove the obstruction and 

 allow the accumulated adrenin to flow into the general circula- 

 tion. A cannula was inserted into the carotid artery, the 

 adrenal glands were exposed through an abdominal incision, 

 and a double ligature passed beneath the organ on each side ; 

 the ligatures were tied on each side of the gland above the vein, 

 so as to form two pedicles. The ligatures were left in place for 

 from ten to thirty minutes, and then released, and the tracing 

 continued. Out of eight experiments, there was no effect on 

 the blood-pressure in three ; in two there was a slight rise after 

 releasing the ligatures ; in the remaining three there was a 

 decided rise of pressure (similar to that which follows the 

 injection of the extract), lasting about three minutes. In one 

 case the effect was repeated by tightening the ligatures a 

 second time, and again releasing them. 



It is important to note that in these experiments after 

 tightening the ligature there was very little, if any, fall of blood- 

 pressure. In fact the experiments merely show that adrenin 

 is poured out into the adrenal veins. 



Dr. Young repeated these experiments and found that even 

 after the lapse of several hours with the blood from the adrenal 

 bodies absolutely excluded from the circulation, there was no 

 appreciable fall of blood-pressure. Austmann and Halliday 

 have also at my suggestion performed a series of experiments 

 in which the adrenals were removed or whose vessels were tied 

 off while the blood-pressure was continuously recorded for many 

 hours. It was found that when the experiment was continued 

 until the animal died the blood-pressure curve was not appre- 

 ciably different from that obtained from an animal simply kept 

 under ether as long as possible. These experiments appear to 

 show conclusively that the secretion of adrenin into the cir- 

 culation is not to be regarded as a factor in the maintenance of 

 the normal blood-pressure. 



But there is another argument which militates powerfully 

 against the theory just mentioned. It was shown by Moore 

 and Purinton that very small doses of adrenin will lower the 

 blood -pressure, not raise it, so that the amount of adrenin 



