THE THYROTROPIC HORMONE 



identified as "thyroidectomy-cells." Their origin is still a 

 matter of disagreement. Some authors believe that they arise 

 at least partly from basophils and either are identical with 

 "castration-cells" or are completely different/ Their rela- 

 tionship to the hypertrophied reserve cells which other au- 

 thors have so frequently noted in the anterior pituitary of 

 animals with thyroid deficiency probably also is close. ^ 



Lebedewa (1936) believed that the pituitary of young 

 thyroidectomized rats contains less thyrotropic hormone than 

 normal. However, her conclusion is not based on enough ex- 

 periments to warrant its acceptance. According to Zeckwer 

 (1936), although the concentration of thyrotropic hormone 

 in the pituitary of thyroidectomized rats is greater than nor- 

 mal in terms of body-weight, the amount present is less than 

 normal in terms of age.*" Chen and van Dyke (1936) investi- 

 gated the anterior pituitary of normal and thyroidectomized 

 rabbits. In littermate normal animals there was no sexual 

 difference in thyrotropic potency. Three months or more 

 after thyroidectomy an increase in the total amount of hor- 

 mone in the hypertrophied anterior pituitary of female rab- 

 bits was noted. Although hypertrophy of the gland was 

 greater in male rabbits, a similar change in potency could not 

 be found. In both sexes the hypertrophied anterior pituitary 

 associated with thyroid deficiency contained more water 

 than the normal gland (total solids 19.1-19.4 per cent com- 

 pared with the normal of 22.2-23.7 per cent). 



The ejects of hypophysectomy on thyroid Junction. — There 

 is little to add to the previous account. Normal thyroid 

 function and all that this implies is markedly but not com- 

 pletely deficient after hypophysectomy. Low-grade thyroid 



^ See chap, i, p. 11. 



5 Altschule and Cooper (1937) recently reported on the changes in the human 

 pituitary associated with operative or spontaneous hypothyroidism. They con- 

 cluded that the number of basophils, often markedly vacuolated, may be 2-4 times 

 as great as normal. Like other authors they believed that hypothyroidism may be 

 due to a primary disturbance of either the pars glandularis or the thyroid. 



^ See also Zeckwer and others (1935). 



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