394 CELLS, TISSUES, AND ORGANISMS 



Talbot ( 1949 ) in terms of square meters of body surface, shows no 

 significant difference with sex or age. Secretion of these compounds is 

 usually increased in Cushings disease but not in hyperplasia with 

 adrenocortical virilism. 



Adrenal cortical function and epiphyseal cartilage. Apparently 

 steroids secreted by the adrenal cortex are necessary for normal bone 

 function. In normal animals the administration of ACTH will produce 

 a marked decrease in the width of epiphyseal cartilage (Becks, Simp- 

 son, Lee, and Evans, 1944). However, some secretion from the adrenal 

 gland is probably required for the maintenance of normal disc func- 

 tion, as epiphyseal widths will decrease in adrenalectomized rats 

 maintained on a 1 per cent sodium-chloride solution. 



If ACTH is administered to hypophysectomized animals, it will 

 lead to a further narrowing of the epiphyseal cartilage ( Marx, Simpson, 

 Li, and Evans, 1943; Marx, Simpson, and Evans, 1944). These authors 

 also demonstrated that when ACTH and growth hormone were both 

 given to hypophysectomized animals, the values were intermediate 

 between those obtained when either hormone was given alone. Further 

 studies have shown that the degree of antagonism between growth hor- 

 mone and ACTH depends upon the ratio of the two hormones em- 

 ployed. 



Geschwind and Li ( 1955 ) have recently studied the efiFect of 17- 

 hydroxy corticosterone ( compound F ) on epiphyseal cartilage. Various 

 doses, administered to normal 27-day-old rats for four days, markedly 

 decreased the epiphyseal cartilage width. A significant efiFect was ob- 

 tained with 100 micrograms of hydrocortisone per day. They also re- 

 ported that large doses of growth hormone (2.5 mg. per day) only 

 partly counteracted the efiFect of 0.5 mg. of hydrocortisone. It was ob- 

 served that whereas 1 mg. of desoxycorticosterone did not alter the 

 response to growth hormone in the hypophysectomized rat, a dose of 

 10 mg. per day markedly decreased the response. 



In summary, it is probable that the adrenal corticoids, secreted in 

 normal amounts, play a permissive role in bone growth in preadoles- 

 cence and adolescence. They do not account for the adolescent spurt in 

 growth. In disease states, excessive amounts of cortoids are catabolic 

 and produce a negative calcium and, as demonstrated experimentally, 

 can antagonize the growth hormone. 



Body weight 



It has been known for centuries, from observations of eunuchs 

 castrated before puberty, that the general body build, musculature, and 

 strength of the human male bear a relationship to testicular function. 

 Tumors of tiie testis have also been observed to produce precocious 



