THE PITUITARY BODY 



but not spermatogenesis may persist in hypophysectomized 

 rats after the injection of oestrone (i,ooo I.U. daily). The 

 fact that certain androgenic substances maintain spermato- 

 genesis in hypophysectomized rats suggests that the normal 

 pituitary gonadotropic hormone necessary for the testis is 

 only that stimulating the interstitial cells. If pituitary secre- 

 tion insures normal function on the part of the interstitial 

 cells, perhaps the secretion of the latter is all that is needed 

 to maintain spermatogenesis. 



The interrelationship between the secretion of gonadotropic 

 hormones and the internal secretions of other glands, i . The 

 thyroid gland. — Reports published after those previously re- 

 viewed still indicate that only exceptionally does there appear 

 to be an important interrelationship between the secretion of 

 gonadotropic hormones and that of the thyroid gland. Gon- 

 adectomy in the guinea pig may be followed by moderate 

 proliferative changes in the thyroid according to Kippen and 

 Loeb (1936). Several authors have studied the effect of thy- 

 roidectomy on the gonads or their response to gonadotropic 

 hormone. Leonard and Leonard (1937) found that thyroid 

 deficiency of about one week's duration probably had no ef- 

 fect on the number of follicles (including vesicular follicles) of 

 the immature rat's ovary. According to Friedgood and Can- 

 non (1936), a marked maturation of the ova in the rabbit's 

 ovary can be observed several weeks after thyroidectomy. 

 Another aspect of the problem is the testing of the ovarian 

 response to gonadotropic hormones after thyroidectomy." 

 Leonard (1936) tested pituitary or urinary extracts in thy- 

 roidectomized or normal rats. The extracts themselves were 

 free from thyrotropic hormone. He concluded that the folli- 

 cle-stimulating phase of the response is greater in thyroid- 

 ectomized animals and that thyroid hormone inhibits the ac- 

 tion of foIHcle-stimulating hormone but not that of luteiniz- 



5^ Benoit (19,36) observed that the response of the testes and secondary sexual 

 organs of the drake to intensive illumination — probably by an indirect neurohumoral 

 mechanism involving the optic nerves and the pars glandularis — could be pre- 

 vented by thyroidectomy. 



[94] 



