242 /• J- Christian 



3. Other Gland Systems 



Many other glands, organs, and organ systems participate in physio- 

 logic adaptation, either directly or in response to increased adrenal or 

 other hormones or diminution thereof. The essential integrative role of 

 the central nervous system has been implicit throughout the foregoing 

 discussion. The gastrointestinal tract and its appendant organs such as the 

 pancreas, liver, and salivary glands also actively participate in adaptation 

 (Ehrich and Seifter, 1948; Selye, 1950; Baker and Bridgman, 1954; Baker 

 and Abrams, 1954). The responses of the stomach to the adrenocortical 

 hormones and to "stress" have been reviewed recently by Gray and Ramey 

 ( 1957) and will not be discussed further here. One example of the participa- 

 tion of the digestive organs in the adaptive responses is the response of the 

 serous glands to increased adrenocortical secretion, first, with a loss of 

 zymogen granules followed by a depletion of cytoplasm nucleic acids 

 (Ehrich and Seifter, 1948) . However, as most of these reactions are second- 

 ary to the increased activity of the pituitary and adrenal cortex, it does 

 not seem appropriate here to dwell on them in detail since the entire organ- 

 ism responds to one degree or another to the physiologic alterations subse- 

 quent to increased activity of the primary adaptive mechanisms. 



D. General Measurements of the Endocrine Adaptive Responses 



1. General 



The actions of and responses to specific hormones and adaptive mecha- 

 nisms have been discussed, but often there are responses in the intact ani- 

 mal that cannot be attributed to a particular hormone or system. The 

 splenic hypertrophy and enlargement of the nucleus pulposus which is seen 

 in mice and voles are examples of such responses (Clarke, 1953 ; Chitty et al., 

 1956; Christian, 1959c). The lymphoid tissue of the spleen is involuted by 

 the adrenal glucocorticoids, but the resultant atrophy is more than offset 

 by increased hematopoiesis in the spleens of mice and voles subjected to 

 social stress or other alarming stimuli (Dawson, 1956). However, it is not 

 known at present what specifically is responsible for the increased hemato- 

 poiesis. This seems to be the proper place to review the physiologic adaptive 

 reactions and to do it in terms of these responses which are found in the 

 intact animal in response to specific stimuli. Wherever possible, the re- 

 sponses will be related to the specific mechanisms responsible for their 

 occurrence. 



It is appropriate first to discuss the stimuli which are known to elicit 

 endocrine adaptive responses. These stimuli have typical dose-time-re- 

 sponse relationships: the severer or the longer the stimulation, the greater 



