THE ENDOCRINE ORGANS, OB DU< rLESS OLAND 



gland. Our investigations must concern the effecl of removal of the 



whole gland or of the injection of extracts of it, and as we proc 1 to 



examine the data, it will become evidenl that most of tl ob- 



served to occui a-, a resnll of injection of extracts of the gland, can 

 be attributed to the medulla. The fatal effects of complete extirpation, 

 on thr other band, are prohably due to removal of the centi 



Adrenalectomy 



Excision of the adrenal gland in most animals is very quickly fatal, 

 the only well-known exception being in the case of the white rat, in which 

 excision of both adrenals may uo1 be incompatible with life. For some 

 time after recovery from the anesthetic the animal upon which double 

 adrenalectomy lias been performed usually behaves in a perfectly non 

 fashion, although it may be less lively and less inclined 1" feed than 

 usual. Very soon, however, generally within twenty-four or forty- 

 eight hours, definite symptoms of muscular weakness are apparent. This 

 weakness soon becomes extreme, and is accompanied by a feeble ]>i, 

 a depression of body temperature, and, later, by dyspnea. After an 

 interval which is never longer than a few days, death supervenes, being 

 sometimes preceded by convulsions. 



When only one adrenal is removed, very few animals succumb: and 



if BOme time is allowed to elapse so that the immediate shock of the 



operation has disappeared, it will usually be found that removal of the 



remaining adrenal, although ultimately fatal, is not so quickly so as 

 when Imih glands are removed at one operation. The reason for this 

 result is that opportunity is given \<>v a compensatory hypertrophy of 



accessory adrenal bodies to occur. Such acc< ry adrenal bodies may 



l.e composed of cortical or medullary tissue, and there is a growing belief 



that th trtical tissue is the more important. Chromaffin tissue is found 



in most animals along the front of the aorta, between th • renal arteries, 

 where it can usually be recognized by Btaining the tissue with chromic acid. 



Sometimes accessory chromaffin tissue is located in distant parts, 



as in the epididymis Of the rat. for example. It is Baid that life can 

 be maintained if one-eighth of the total amount of the adrenal subsl 



present in the body. Attempts to prolong lib adrenalectomy 



by adrenal transplantation have almost invariably met with negative 



results, because the grafl under rapid process of necrosis and dis- 



appears; although it is said that transplantation may sometiim 

 cessfiilly accomplished if the grafting is done into the kidney. Adminis- 

 tration of suprarenal extract is also without definit< 

 adrenalectomy. 



