218 ./• ./• Christian 



response to ACTH-secrcting pituitary tumors were from the cortictes of 

 adrenals without X-zones (Bahn et al., 1957). On the other hand, Delost 

 (1951) suggests that the X-zone may be that part of the cortex responsible 

 for secreting the adrenal androgens which maintain the activity of the vas 

 deferens and ventral prostate of meadow voles (Microtus arvalis) in winter 

 and in adrenalectomized voles (Delost, 1954). The evidence for this sug- 

 gestion is tenuous and requires further investigation and confirmation. The 

 function of the X-zone, if there is one, remains undiscovered at the present 

 time. 



3. Adrenocortical-Gonadal Interrelationships 



This problem has been discussed by Jones (1957), and the reader is re- 

 ferred to this work for a more detailed discussion of this intriguing problem. 



There is a very close relationship between the cells of the adrenal cortex 

 and those of the gonadal cells with respect to their origin and function. 

 Both groups of cells arise from the embryonic genital ridge of the coelomic 

 mesothelium, both secrete steroid hormones in response to stimulation by 

 pituitary hormones; and there is a definite overlap in their functional 

 capacities. Even though the adrenal cortex is believed to be a source of sex 

 steroids, gonadectomy in normal animals is followed by complete involution 

 of the sex accessories to the immature condition (Jones, 1957) . The involu- 

 tion occurs even in mammals such as mice and rats in which weakly andro- 

 genic Ci9 steroids normally are an appreciable portion of the cortical secre- 

 tory product (Dorfman and Shipley, 1956; Wilson et al, 1958). Similarly, 

 the sex accessories and secondary sex characteristics which are under hor- 

 monal control fail to develop in the prepubertal castrate mammals (Bur- 

 rows, 1949; Jones, 1957) . Finally, the transplantation of the adrenal to the 

 uterus does not alter the morphology of that part of the uterus or of the 

 vagina which is in direct contact with the graft (Sakiz, 1956) . These facts 

 cast considerable doubt on their ability of the normal adrenal cortex of any 

 species to secrete steroids with strongly androgenic or estrogenic actions. 

 There is much evidence, however, that under certain circumstances the 

 adrenal cortex is capable of assuming sex steroidal activity, for example, in 

 the androgenital syndrome and similar virilizing conditions in man (Dorf- 

 man and Shipley, 1956; Gallagher et al, 1958). A striking increase in the 

 secretion of weakly androgenic adrenal steroids may account for these 

 effects (Jones, 1957) , but they may also result from the conversion of adre- 

 nal androgens into testosterone in these circumstances (Dorfman, 1960). 

 These conditions are usually associated with functional tumors of the cortex 

 or with a marked increase in the secretion of ACTH with an accompanying 

 cortical hyperplasia, but without an appreciable increase in the secretion of 



