2. Endocrines and Populations 255 



development of granulation tissue (Selye, 1955; Dougherty and Schneebeli, 

 1955) . These hormones, however, also inhibit the anti-inflammatory action 

 of cortisone, hydrocortisone, and corticosterone and may enhance the local 

 inflammatory response by increasing the susceptibility of the cells to the 

 inflaming stimulus (Dougherty and Schneebeli, 1955). Therefore, if there 

 is a reduction in the secretion of growth hormone with a simultaneous in- 

 crease in the production of ACTH and the adrenocortical steroids, there 

 will not only be a direct suppression of the inflammatory responses to infec- 

 tion or injury, but also a withdrawal of the factors which ordinarily would 

 stimulate such activity. The effects of various alarming stimuli or hormones 

 on inflammation and granulation in the intact animal have been studied 

 and measured by using experimental granulomas (Meier et at, 1950; Selye 

 and Bois, 1954; Robert and Nezamis, 1957; Christian and Williamson, 

 1958) or other means of inducing inflammation and granulation. It has been 

 shown that in addition to suppressing inflammation the carbohydrate- 

 active corticoids also suppress the formation of granulation tissue and 

 healing, primarily by preventing connective tissue growth. There can be 

 little doubt that the normal defenses against infection are severely depressed 

 in stressed animals. 



c. Antibody formation. Antibodies are formed mainly in the lymphatic 

 tissues (Kenning and Van der Slikke, 1950; Kass et al., 1953a; Kelsall and 

 Crabb, 1958) . One school maintains that this function resides primarily in 

 the plasma cells, w^hile another group holds that lymphatic cells in general 

 are capable of manufacturing antibodies (Kenning and Van der Slikke, 

 1950; Dougherty, 1953; Kelsall and Crabb, 1958). We do not intend to 

 enter into this controversy at the present time, but it seems relatively 

 certain that the lymphoid tissues are primarily responsible for the produc- 

 tion of antibodies. A variety of experiments have shown that injected 

 corticoids or the increased secretion of endogenous corticoids, brought 

 about either by injected ACTH or in response to alarming stimuli, markedly 

 suppress the formation of antibodies (Kass et al., 1953a) . Protein manufac- 

 ture, and therefore the formation of antibodies, requires the presence of 

 nucleic acids in the cells, especially in the cytoplasm, and antibody forma- 

 tion is normally associated with an increase in nucleic acid content of the 

 lymphoid organs (Kass et al., 1953a; Kelsall and Crabb, 1958). Therefore, 

 when there is interference with nucleic acid metabolism or its formation, 

 there is an accompanying reduction in the rate of formation of antibodies 

 (Kass et al., 1953a; Kelsall and Crabb, 1958). We have seen that in addi- 

 tion to actually destroying lymphoid tissue, the glucocorticoids reduce the 

 PNA content of the remaining lymphatic cells. The ability of the reticulo- 

 endothelial system, and possibly other cells, to dispose of phagocytized 

 particulate material is also impaired (Thomas, 1953) even though phago- 



