THE SUPRARENAL SYSTEM 213 



The increase in the amount of lymph excreted from the 

 thoracic duct which, according to Camus, follows the intravenous 

 injection of adrenalin, is in all probability largely due to changes 

 in the circulatory conditions. It cannot be denied, however, that 

 adrenalin may possibly exercise an effect upon the formation of 

 the lymph itself. 



After the subcutaneous injection of adrenalin, oedema fre- 

 quently appears at the site of injection, and the lymphatics lead- 

 ing away from it are sometimes found to be full. If the same 

 quantity of adrenalin is employed, but in a very dilute solution, 

 the cedematous swelling becomes much more marked and may 

 last for some time. These phenomena must be largely due to a 

 reduction in resorption, brought about by a local constriction of 

 the vessels at the site of injection. This accounts for the fact 

 that the subcutaneous injection of adrenalin produces so little 

 effect upon the blood-pressure ; to a certain extent, the substance 

 blocks the way of its own resorption. 



The gradual resorption of the adrenalin in minimal quantities 

 explains why it is that the subcutaneous injection of even large 

 doses does not produce a rise in blood-pressure, but is followed 

 by considerable periodical changes in pressure (Biedl). Lowi 

 and Meyer found that when methylaminoketone, which is closely 

 related to adrenalin, is injected subcutaneously in large doses, 

 the blood-pressure becomes elevated and will continue so for 

 over an hour. This result is explained by the fact that methyl- 

 aminoketone is considerably less active than adrenalin, hence 

 the possibility of its better resorption. Meltzer and Auer found 

 that the intramuscular injection of adrenalin produced an increase 

 in blood-pressure ; but Patta pointed out that, whether given intra- 

 muscularly or subcutaneously, the injection of adrenalin is not 

 followed by a rise in blood-pressure in animals, unless the sub- 

 stance is introduced by accident into a blood-vessel. In man, 

 the subcutaneous injection of adrenalin produces an increased 

 blood-pressure (Falta). 



A. Exner showed that the intraperitoneal injection of 

 adrenalin is followed by a reduced resorption on the part of the 

 lymphatics of the peritoneum. For it is not only those toxins 

 which enter the system by way of the blood-vessels, which under- 

 go a tardy resorption after the introduction of adrenalin into the 

 peritoneum or into the stomach ; the same is seen in the case of 

 substances which, owing to their physical properties, reach the 

 blood-stream through the agency of the lymphatics. 



Langley found that the sweat glands of the cat were un- 

 affected both by the intravenous injection of adrenalin and by 

 its subcutaneous introduction into the ball of the paw. Elliott 

 found that a subcutaneous injection of .025 mg. of adrenalin did 

 not provoke secretion of the sweat glands in the palm of the 

 hand in man ; on the contrary, owing to the extreme local anaemia, 



