SIGNIFICANCE OF THE SUPRARENAL GLANDS 137 



not in the denervated gland, so that at the end of some hours a marked 

 deficiency in the store of the former is established. 



In the dog and cat there seems to be no crossing of epinephrin secre- 

 tory fibers from one splanchnic to the opposite suprarenal. It has been 

 stated by Kahn(6) and by Nishi(fr) that in the rabbit the right suprarenal 

 seems to derive from the left splanchnic a portion of the nerve supply 

 concerned in changes in the epinephrin store and in the liberation of 

 epinephrin. The much greater difficulty experienced by Stewart and 

 Rogoff (c) in producing a marked differential effect on the epinephrin store 



Fig. 7. Intestine tracings constituting a small sample of those used in the assay 

 of suprarenal blood specimens from a cat before and after transection of the cord above 

 the origins of the 6th pair of cervical nerves. At 27, 29 and 33 Ringer's solution was 

 replaced by indifferent (venous) blood and this at 28 by indifferent blood to which was 

 added "adrenalin" to make a concentration of 1:660,000; at 30 by a suprarenal blood 

 specimen collected 5V 2 minutes after section of the cord; at 34 by indifferent blood to 

 which was added "adrenalin" to make a concentration of 1:530,000. All the blood 

 specimens were diluted with 3 volumes Ringer's solution (the "edrenalin" bloods after 

 adding the "adrenalin"). The suprarenal blood was assayed at 1:700,000, correspond- 

 ing to an output of 0.00021 mgm. epinephrin per kgm. per minute, precisely the same 

 as that given by a suprarenal specimen collected before cord section, although the 

 concentration of the latter specimen was of course much less (1:6,000,000), corre- 

 sponding to the much greater blood flow associated with the higher pressure. (Re- 

 duced to three-sevenths.) (After Stewart and Rogoff, Am. J. Physiol) 



of the two suprarenals in these animals, after section of the splanchnics 

 on one side, tends to confirm this suggestion. 



With regard to the position of the central nervous mechanism con- 

 trolling the epinephrin secretion, the best established fact is that, after 

 section of the cervical cord in acute experiments in the cat the output may 

 not be at all diminished (Stewart and Rogoff 1917, 1920 (t) Fig. 7. 

 This result is the rule after bloodless elimination of the upper parts of the 

 central nervous system, by ligation (in cats) of both carotids and verte- 

 brals, or of the innominate, left subclavian proximal to the origin of the 

 vertebral, and other arteries supplying the head (Stewart, Guthrie, Burns 

 and Pike, Fig. 8). In dogs and monkeys the output was diminished in 

 acute experiments by cervical cord section owing, it is suggested, to 

 spinal shock of an epinephrin-secreting center in the upper part of the 



